Electrical Manual – 2013 Light Duty Full Size C/K Trucks

Voltage Reduction Mode ............................................................................................................................... A-21 Auxiliary Battery Charging (TP2) .................................................................................................................... A-22 Table of Contents Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE 3 3 Page Electrical Manual – 2012 Light Duty Full Size C/K Trucks ElEctrical Manual - 2012 light Duty Full SizE c/K trucK SeCTION a, cont’d. INSTRUMeNT PaNeL CLUSTeR (IPC) OPeRaTION Charge Indicator Operation ................................................................................................................................... A-22 Battery Voltage Gauge Operation ......................................................................................................................... A-22 Service Battery Charging System ......................................................................................................................... A-22 eNgINe IDLe UP Elevated Idle / Pto / High Idle Are All Different Options ........................................................................................ A-23 Elevated Idle .................................................................................................................................................. A-23 PTO (power take-off) ..................................................................................................................................... A-23 High Idle......................................................................................................................................................... A-23 Adding PTO Option To A Vehicle Without The Option . Condition/Concern ........................................................................................................................................ A-24 Recommendation/Instructions ...................................................................................................................... A-24 IMMOBILIzeR Remote Vehicle Immobilizer .................................................................................................................................. A-25 Remote Vehicle Immobilizer Schematic ................................................................................................................ A-25 Remote Vehicle Location Drawing ........................................................................................................................ A-26 FORWaRD LIgHTINg Front of Vehicle Components X88 ................................................................................................................................................................. A-27 Z88 ................................................................................................................................................................. A-28 Z75 ................................................................................................................................................................. A-29 Table of Contents Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE 4 4 Page Electrical Manual – 2012 Light Duty Full Size C/K Trucks ElEctrical Manual - 2012 light Duty Full SizE c/K trucK FORWaRD LIgHTINg (SeCTION a), cont’d. Lamp Harness Routing HP2 ................................................................................................................................................................ A-30 X88 ................................................................................................................................................................. A-31 Z75 ................................................................................................................................................................. A-32 Z88 ................................................................................................................................................................. A-33 Headlamp Left T4Q .......................................................................................................................................................... A-34 Z88 ........................................................................................................................................................... A-35 High Beam (X88) ...................................................................................................................................... A-36 Low Beam (X88)....................................................................................................................................... A-37 Right T4Q .......................................................................................................................................................... A-38 Z88 ........................................................................................................................................................... A-39 High Beam (X88) ...................................................................................................................................... A-40 Low Beam (X88)....................................................................................................................................... A-41 Forward Headlamp Replacement Chevrolet ................................................................................................................................................. A-42 GMC ........................................................................................................................................................ A-43 HD Diesel ................................................................................................................................................. A-44 Headlamp Bulb Replacement Chevrolet ................................................................................................................................................. A-45 GMC ........................................................................................................................................................ A-46 Bulb Replacement ................................................................................................................................................. A-47 Table of Contents Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE 5 5 Page Electrical Manual – 2012 Light Duty Full Size C/K Trucks ElEctrical Manual - 2012 light Duty Full SizE c/K trucK SeCTION a, cont’d. ReaRWaRD LIgHTINg Separate Stop and Turn Signals .......................................................................................................................... A-48 CHMSL ................................................................................................................................................................. A-51 DOMe LaMP ................................................................................................................................................................ A-52 SNOW PLOW PReP PaCKage (VYU) eLeCTRICaL PROVISIONS Emergency Roof-Mounted Lamp Switch .............................................................................................................. A-53 VYU Generators .................................................................................................................................................... A-53 Accessory Harness Grommet ............................................................................................................................... A-53 Forward Lamp Harness In-Line Connectors ......................................................................................................... A-53 Backup Lamp Power Feed.................................................................................................................................... A-53 aCCeSSORY HaRNeSS gROMMeT ......................................................................................................................... A-54 VYU HOLe LOCaTION................................................................................................................................................. A-55 ROOF MOUNTeD BeaCON (TRW) Installation Instructions — Emergency Vehicle Roof Panel Lamp ........................................................................ A-56 Option A: Roof Wires Directly to Accessory .................................................................................................. A-57 Option B: Use Wiring Harness Package 12150250. Obtain from GM Service Parts through the GM Dealership .................................................................... A-57 ROOF CONSOLe RePLaCeMeNT ............................................................................................................................. A-58 Table of Contents Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE 6 6 Page Electrical Manual – 2012 Light Duty Full Size C/K Trucks ElEctrical Manual - 2012 light Duty Full SizE c/K trucK ROOF MOUNTeD BeaCON (SeCTION a), cont’d. ROOF MOUNTeD BeaCON (TRW) Restoring Power .................................................................................................................................................... A-59 Option B ................................................................................................................................................................ A-60 Maintenance.......................................................................................................................................................... A-61 PaRK NeUTRaL SIgNaL Steering Column Components.............................................................................................................................. A-62 Shift Lock Control Schematic ............................................................................................................................... A-63 ReMOTe STaRT STOP ................................................................................................................................................ A-64 TRaILeR BRaKe DeSCRIPTION aND OPeRaTION Trailer Brake Controls Description And Operation ................................................................................................ A-65 Manual Trailer Brake Apply ............................................................................................................................ A-65 Trailer Gain Adjustment ................................................................................................................................. A-66 Trailer Brake Control Panel ............................................................................................................................ A-67 Driver Information Indicators and Messages ................................................................................................. A-67 Trailer Connected..................................................................................................................................... A-67 Check Trailer Wiring And Trailer Not Connected ..................................................................................... A-67 Service Trailer Brake System ................................................................................................................... A-68 Trailer Gain And Output Display .............................................................................................................. A-68 Trailer Brake Control (JL1 except 10 Series) ................................................................................................. A-69 Trailer Connector ................................................................................................................................................... A-70 Rear Frame and Underbody Components (20/30 Series) ..................................................................................... A-72 Trailer Brake Control Module (JL1 except 31 Series) ............................................................................................ A-73 Table of Contents Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE 7 7 Page Electrical Manual – 2012 Light Duty Full Size C/K Trucks ElEctrical Manual - 2012 light Duty Full SizE c/K trucK TRaILeR BRaKe (SeCTION a), cont’d. Rear Frame and Underbody Components (31 Series) .......................................................................................... A-74 Trailer Brake Control Module (JL1 with 31 Series) ................................................................................................ A-75 Chassis Harness (31 Series) ................................................................................................................................. A-76 Trailer Brake Control Relay (JL1) ........................................................................................................................... A-77 Rear Frame and Underbody Components (10 Series) .......................................................................................... A-78 Trailer Connector (except MEX or EXP)................................................................................................................. A-79 Trailer Brake Installation of Aftermarket Trailer Brake Controller ........................................................................................ A-80 Auxiliary Power (Applies to All LD & 07-09 HD’s Only) ............................................................................ A-83 Installation Instructions ............................................................................................................................ A-85 Warranty Information ............................................................................................................................... A-85 Table of Contents Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE 8 8 Page Electrical Manual – 2012 Light Duty Full Size C/K Trucks ElEctrical Manual - 2012 light Duty Full SizE c/K trucK SeCTION B FUSe BLOCK Underhood Label .................................................................................................................................................... B-1 Usage Diesel ......................................................................................................................................................... B-2 Gas ............................................................................................................................................................ B-6 Underhood Top View Diesel ............................................................................................................................................................. B-11 Gas ................................................................................................................................................................ B-12 Underhood Bottom View ....................................................................................................................................... B-13 X1 ................................................................................................................................................................. B-14 X2 ................................................................................................................................................................. B-16 X3 ................................................................................................................................................................. B-19 X4 ................................................................................................................................................................. B-21 X5 ................................................................................................................................................................. B-23 X6, X7 (except TP2), X7 (TP2), X8 (except JL1), X8 (JL1) .............................................................................. B-25 I/P Label .............................................................................................................................................................. B-26 Top View ........................................................................................................................................................ B-28 Bottom View .................................................................................................................................................. B-29 X1 ................................................................................................................................................................. B-30 X2 (except MEX) ............................................................................................................................................ B-32 X3 ................................................................................................................................................................. B-33 X4 ................................................................................................................................................................. B-34 Table of Contents Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE 9 9 Page Electrical Manual – 2012 Light Duty Full Size C/K Trucks ElEctrical Manual - 2012 light Duty Full SizE c/K trucK FUSe BLOCK (SeCTION B), cont’d. Auxiliary (HP2) Label .............................................................................................................................................................. B-36 Top View ........................................................................................................................................................ B-37 Bottom View .................................................................................................................................................. B-38 Auxiliary X1 (HP2) .................................................................................................................................................. B-39 Auxiliary X2 (HP2) .................................................................................................................................................. B-41 Auxiliary X3 (HP2), Auxiliary X4 (HP2), Auxiliary Fuse Holder (HP2)...................................................................... B-42 Mobile Radio, Top View (9L4), Device Usage........................................................................................................ B-43 Mobile Radio (9L4) ................................................................................................................................................ B-44 Fuse Holders Device Usage (Gas and Diesel) ..................................................................................................................... B-45 X1 (Gas except 9L4), X1 (Diesel or Gas with 9L4), X2 (Gas with TP2), X2 (Diesel or Gas except LU3), X2 (LU3), X2 (Gas except LU3) ................................................................................................................ B-46 X2 (Diesel), X3 (9L4), X3 (Diesel), X4 (TP2), X4 (Diesel), X4 (Diesel with K76 or YF2) .................................... B-47 JUNCTION BLOCK Left I/P Label .............................................................................................................................................................. B-48 Top View ........................................................................................................................................................ B-49 Bottom View .................................................................................................................................................. B-50 X1 (except MEX) ............................................................................................................................................ B-51 X2 (except MEX) ............................................................................................................................................ B-54 X3 (except MEX) ............................................................................................................................................ B-56 X4 (except MEX) ............................................................................................................................................ B-57 X5 (SPO Alarm or SPO Heated Seats)........................................................................................................... B-58 Table of Contents Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE 10 10 Page Electrical Manual – 2012 Light Duty Full Size C/K Trucks ElEctrical Manual - 2012 light Duty Full SizE c/K trucK JUNCTION BLOCK, Left I/P (SeCTION B), cont’d. X7 (JF4) ......................................................................................................................................................... B-59 X8 (except MEX) ............................................................................................................................................ B-60 X9 (except MEX) ............................................................................................................................................ B-61 X10 (except MEX) .......................................................................................................................................... B-62 X11 (except MEX) .......................................................................................................................................... B-63 X12 (except MEX) .......................................................................................................................................... B-64 X13 (AN3) ....................................................................................................................................................... B-65 X14 (5Y0, 5X7, 9L4, SPO DVD or SPO Heated Seats) .................................................................................. B-66 Right I/P Top View ........................................................................................................................................................ B-67 Wire Entry ...................................................................................................................................................... B-68 X2 ................................................................................................................................................................. B-71 X3 ................................................................................................................................................................. B-72 X4 ................................................................................................................................................................. B-74 X5 ................................................................................................................................................................. B-75 X6 ................................................................................................................................................................. B-76 Rear Lamps ........................................................................................................................................................... B-77 X1 ................................................................................................................................................................. B-78 X2 ................................................................................................................................................................. B-79 X3 ................................................................................................................................................................. B-80 X4 ................................................................................................................................................................. B-81 Table of Contents Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE 11 11 Page Electrical Manual – 2012 Light Duty Full Size C/K Trucks ElEctrical Manual - 2012 light Duty Full SizE c/K trucK BODY CONTROL MODULe (SeCTION C) BODY CONTROL MODULe (BCM) X1 ............................................................................................................................................................................ C-1 X2 ............................................................................................................................................................................ C-2 X3 ............................................................................................................................................................................ C-3 X4 ............................................................................................................................................................................ C-4 X5 ............................................................................................................................................................................ C-5 X6 ............................................................................................................................................................................ C-6 X7 (except MEX or A52) .......................................................................................................................................... C-7 X500 LeFT FRONT DOOR HaRNeSS TO BODY HaRNeSS (YE9 or HP2, without AN3 or DL3) ............................... C-9 X502 LeFT FRONT DOOR HaRNeSS TO BODY HaRNeSS (ASF with AN3 or DL3, and except YE9) .................... C-11 X501 LeFT FRONT DOOR HaRNeSS TO BODY HaRNeSS (YE9 or HP2, without AN3 or DL3) ............................. C-12 X600 RIgHT FRONT DOOR HaRNeSS TO BODY HaRNeSS (YE9 or HP2, without AN3 or DL3) ........................... C-14 X601 RIgHT FRONT DOOR HaRNeSS TO BODY HaRNeSS (ASF) ......................................................................... C-16 X700 Body Harness to Left Rear Door Harness (Crew Cab).......................................................................................... C-17 Left Rear Door Harness to Body Harness (Extended Cab) ................................................................................... C-19 X800 Body Harness to Right Rear Door Harness (Crew Cab) ....................................................................................... C-21 Right Rear Door Harness to Body Harness (Extended Cab) ................................................................................ C-23 X500 DRIVeR DOOR HaRNeSS TO BODY HaRNeSS (ASF).................................................................................... C-25 X600 PaSSeNgeR DOOR HaRNeSS TO BODY HaRNeSS (ASF) ........................................................................... C-26 X700 BODY HaRNeSS TO LeFT ReaR DOOR HaRNeSS ....................................................................................... C-27 X800 BODY HaRNeSS TO RIgHT ReaR DOOR HaRNeSS .................................................................................... C-29 Table of Contents Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE 12 12 Page Electrical Manual – 2012 Light Duty Full Size C/K Trucks ElEctrical Manual - 2012 light Duty Full SizE c/K trucK SeCTION C, cont’d. eNgINe CONTROL MODULe (eCM) X1 Diesel ............................................................................................................................................................. C-31 HP2 ................................................................................................................................................................ C-33 L96 ................................................................................................................................................................. C-35 LU3 ................................................................................................................................................................ C-37 L20, L9H, LC9 or LMG................................................................................................................................... C-39 X2 Diesel ............................................................................................................................................................. C-41 HP2 ................................................................................................................................................................ C-43 L96 ................................................................................................................................................................. C-45 LMG, LC9, LY5, LH6, L76 or L9H without Y91 .............................................................................................. C-47 LU3 ................................................................................................................................................................ C-49 LY2, LY6 or L9H with Y91 .............................................................................................................................. C-51 X3 HP2 ................................................................................................................................................................ C-53 L96 ................................................................................................................................................................. C-55 LGH or LML ................................................................................................................................................... C-57 TRaNSMISSION CONTROL MODULe (TCM) M30 ....................................................................................................................................................................... C-59 MW7 ...................................................................................................................................................................... C-61 Table of Contents Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE 13 13 PAGE E L E CTRICAL M ANUAL -2012 L IG HT D UTY F ULL S IZ E C /K T RUC K RADIO X1 UYS................................................................................................................................................................ C-63 Without UYS or UL5 ...................................................................................................................................... C-64 X2 (Without UYS or UL5) ....................................................................................................................................... C-65 X3 (U42) ................................................................................................................................................................. C-66 X4 (UYS) ................................................................................................................................................................ C-67 TRAILER CONNECTOR (except MEX or EXP) ............................................................................................................ C-68 SECTION C, contíd. 13 PAGE E L E CTRICAL M ANUAL -2012 L IG HT D UTY F ULL S IZ E C /K T RUC K RADIO X1 UYS................................................................................................................................................................ C-63 Without UYS or UL5 ...................................................................................................................................... C-64 X2 (Without UYS or UL5) ....................................................................................................................................... C-65 X3 (U42) ................................................................................................................................................................. C-66 X4 (UYS) ................................................................................................................................................................ C-67 TRAILER CONNECTOR (except MEX or EXP) ............................................................................................................ C-68 SECTION C, contíd. Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-1 A-1 PAGE Overview BODY CONTROL SYSTEM DESCRIPTION AND OPERATION The body control system consists of the body control module (BCM), communications, and various input and outputs. Some inputs, outputs and messages require other modules to interact with the BCM. The BCM also has discrete input and output terminals to control the vehicle's body functions. The BCM is wired to the GMLAN high speed serial data buss and the GMLAN low speed serial data buss and acts as a gateway between them. If the BCM does not communicate the vehicle will not start due to the inability of the engine control module (ECM)/ powertrain control module (PCM) and theft deterrent module (TDM) to communicate without the BCM providing the gateway function. POWER MODE DESCRIPTION AND OPERATION Serial Data Power Mode Master Power to many of this vehicles circuits is controlled by the module that is designated the power mode master (PMM). This vehicles PMM is the body control module (BCM). The ignition switch is a low current switch with multiple discrete ignition switch signals to the PMM for determination of the power mode that will be sent over the serial data circuits to the other modules that need this information. The PMM will also activate relays and other direct outputs of the PMM as needed. The PMM determines which power mode (Off, Accessory, Run, Crank Request) is required, and reports this information to other modules via serial data. Modules which have switched voltage inputs may operate in a default mode if the PMM serial data message does not match what the individual module can see from its own connections. The PMM receives ignition switch signals to identify the operators desired power mode. The PMM Power Mode Parameters table below illustrates the correct state of these input parameters (circuits) in correspondence to the ignition switch position: PMM Power Mode Parameters (continued on next page) Ignition Switch Position Power Mode Transmitted Ign. Off / Run / Crank (Run Crank Ignition 1 Voltage Circuit) Ignition Accessory / Run (Accessory Voltage Circuit) Ignition Run/Crank (Ignition 1 Voltage Circuit) Off Key Out Off Key Out/ACC Inactive Inactive Off Key IN Off Key In/Off Inactive Inactive Accessory Accessory Key Out/ACC Active Inactive Run Run Run Active Active Start Crank Request Crank Inactive Active Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-2 A-2 PAGE Relay Controlled Power Mode The body control module (BCM) uses the discrete ignition switch inputs Run/Crank Ignition 1 Voltage, Accessory Voltage, and Ignition 1 Voltage, to distinguish the correct power mode. The BCM, after determining the desired power mode, will activate the appropriate relays for that power mode. The RAP relay remains on for a timed period after the Ignition key is removed. Refer to Retained Accessory Power Description and Operation for more information on the retained accessory power (RAP) function. BCM Awake/Sleep States The body control module (BCM) is able to control or perform all of the BCM functions in the awake state. The BCM enters the sleep state when active control or normal monitoring of system functions has stopped and a time limit has passed. The BCM must detect certain wake-up inputs before entering the awake state. The BCM monitors for these inputs during the sleep state. The BCM will enter the awake state if any of the following wake-up inputs are detected: • Activity on the serial data line • Detection of a battery reconnect • Any door open signal • Headlamps ON • Key-in-ignition • Ignition ON • Park lamps ON • Keyless entry or remote start message The BCM will enter a sleep state when all of the following conditions exist: • The ignition switch is OFF, key out. • No activity exists on the serial data line. • No outputs are commanded. • No delay timers are actively counting. • No wake-up inputs are present. If all these conditions are met, the BCM will enter a low power or sleep condition. Overview (cont'd) (continued on next page) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-3 A-3 PAGE RETAINED ACCESSORY POWER DESCRIPTION AND OPERATION Retained Accessory Power (RAP) The retained accessory power (RAP) system allows specific vehicle functions to operate for a specific amount of time after the ignition switch is turned OFF. The BCM monitors the ignition switch position, battery condition, and each door open/closed status to determine whether RAP should be initiated or terminated. RAP is controlled with 2 different methods; serial data and relay control. The relay is internal to the BCM and feeds multiple external components. Some modules receive a RAP message over the serial data circuits. Serial data controlled RAP is deactivated as required by their modules RAP power mode operation. Other subsystems are activated directly by the BCM through the internal RAP relay. Components and systems that are active in RAP are also activated anytime the ignition is any position other than OFF regardless of the door switch signals. The BCM sends a serial data power mode message ending the RAP function when one of the following conditions are met: • The BCM receives an input indicating the opening of any passenger compartment door after the ignition key is out of the ignition. Important: The only door that will turn off the radio during RAP is the driver door. This is a function of the radio and will still turn off after the time limit. • The BCM internal timer for RAP expires after approximately 10 minutes. The BCM detects a decrease in battery voltage below a calibrated limit. Relay Control of Retained Accessory Power (RAP) The body control module (BCM) keeps the internal RAP relay energized during all power modes, except Off-Awake and Crank. The relay is also energized for approximately 10 minutes after shutting the ignition OFF and removing the key, providing no door is opened. The BCM will de- energize the internal RAP relay at the same time the serial data message is sent to end RAP. When the internal RAP relay is energized voltage is applied on the accessory voltage circuit at BCM harness connector X2 terminal 22. The devices powered by the internal RAP relay during the RAP power mode are as follows: • Sunroof module - (CF5) • Mobile radio fuse block, relay A - (9L4) • Sliding rear window switch - (A48) • Window switches, driver and passenger - (A31 w/o AN3) Overview (cont'd) (continued on next page) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-4 A-4 PAGE Serial Data Control of Retained Accessory Power (RAP) RAP systems controlled by serial data are as follows: Power Windows If equipped with RPO AN3 the front window switches are separate modules that operate the windows on their respective side of the vehicle and receive the serial data RAP messages. Window RAP activation/termination timing is the same as relay operation. Vehicle Communication Interface Module (VCIM) (Onstar®) VCIM RAP activation/termination is the same as radio operation with 1 exception; if there is an active call when the ignition key is turned off the VCIM will remain in RAP mode and keep the radio in RAP mode until the call is terminated. Radio Radio RAP activation/termination is the same as relay operation with 1 exception; the only door switch that will turn off the radio during RAP is the driver door open switch. Overview (cont'd) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-5 A-5 PAGE Backup Alarm/Camera - Backup Alarm Relay Schematic For installation of backup alarm/camera on vehicles without option code 8S3 [Factory backup alarm], connection can be made at the rear lighting connector X1 or X2. The backup lamps come on with perimeter lighting and key fob acknowledgement, to avoid operation upon entry and exit from the vehicle there are two options... 1. Have the dealer load the SFW [backup alarm calibration] software in your body computer. This calibration disables the perimeter lighting feature and will eliminate the activation of the back-up alarm when exiting and/or key fob activation. Note there is a fee for the dealers to perform this service. The back-up alarm can then be wired directly to the back-up lamp circuit directly and will operate (alarm sounded) when the vehicle is in reverse and the back-up lamps are illuminated. OR 2. Add an ignition controlled relay to connect the backup alarm/camera to the backup lamp circuit so that it will only operate when the ignition is on and the backup lamps are on (continued on next page) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-6 A-6 PAGE Backup Alarm/Camera - Backup Lamp Schematic Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-7 A-7 PAGE Backup Alarm/Camera - Chassis Harness (31 Series) Routing Diagram (1) Trailer Brake Control Relay (JL1) (2) J422 (JL1) (3) Trailer Connector (4) J331 (Diesel without NQZ/LY6) (5) X300 (LY6) (6) X300 (Diesel) (7) J411 (JL1) (8) Junction Block - Rear Lamps (9) G401 (10) J338 (JL1) (11) G300 (12) J300 (LY6 without NQZ) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-8 A-8 PAGE Backup Alarm/Camera - Junction Block - Rear Lamps Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-9 A-9 PAGE Backup Alarm/Camera - Junction Block - Rear Lamps X1 Connector Part Information Harness: Chassis OEM: 15317304 Service: 19167008 Description: 8-Way F GT 280 Sealed (BU) Terminal Part Information Pins: A, C, D, G, H Terminal/Tray: 15304716/8 Core/Insulation Crimp: 2/1 Release Tool/Test Probe: 15315247/J-35616-4A (PU) Pins: B, E Terminal/Tray: 15304717/8 Core/Insulation Crimp: 4/1 Release Tool/Test Probe: 15315247/J-35616-4A (PU) Pin Wire Color Circuit No. Function A 0.8 YE 18 Left Rear Stop/Turn Lamp Supply Voltage B 2 BK 2150 Ground C 0.8 L-GN 24 Backup Lamp Supply Voltage D 0.8 BN 2609 Right Rear Park Lamps Supply Voltage E 2 BK 1750 Ground (except MEX) 3 BK 1750 Ground (MEX) F -- -- Not Used G 0.8 BN 2509 Left Rear Park Lamps Supply Voltage H 0.8 D-GN 19 Right Rear Stop/Turn Lamp Supply Voltage Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-10 A-10 PAGE Backup Alarm/Camera - Junction Block - Rear Lamps X2 Connector Part Information Harness: Chassis OEM: 15317305 Service: 15306338 Description: 8-Way F GT 280 Sealed (GY) Terminal Part Information Pins: A, C, D, G, H Terminal/Tray: 15304716/8 Core/Insulation Crimp: 2/1 Release Tool/Test Probe: 15315247/J-35616-4A (PU) Pins: B, E Terminal/Tray: 15304717/8 Core/Insulation Crimp: 4/1 Release Tool/Test Probe: 15315247/J-35616-4A (PU) Pin Wire Color Circuit No. Function A-B -- -- Not Used C 0.8 BK 1750 Ground D -- -- Not Used E 0.8 BN 2509 Left Rear Park Lamps Supply Voltage F 0.8 L-GN 24 Backup Lamp Supply Voltage G -- -- Not Used H 0.8 YE 18 Left Rear Stop/Turn Lamp Supply Voltage Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-11 A-11 PAGE Battery Isolator - Medium Duty Battery Isolator Schematic Battery Isolator Battery isolation can be done in a number of ways. In this section we show you two ways that GM does it. On medium duty trucks we have a diode isolator component that places in line diodes in the battery charge lead going to the alternators. On CK trucks we have a relay isolation scheme. These drawings are provided to show you how you might accomplish your application. Medium Duty Battery Isolator Schematic Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-12 A-12 PAGE Battery Isolator - Auxiliary Battery Schematic Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-13 A-13 PAGE Battery/Ignition/Ground Feeds - Installation of Electrical Aftermarket Accessories - Battery, Ignition and Ground Feeds Subject: Installation of Electrical Aftermarket Accessories -- Battery, Ignition and Ground Feeds -- Do Not Splice into Wiring Harness (Install Diode to Solenoid/Relay to Suppress Voltage Spikes) Models: 2007-2010 Cadillac Escalade, Escalade ESV, Escalade EXT 2007-2010 Chevrolet Avalanche, Silverado, Suburban, Tahoe 2008-2010 Chevrolet Express 2007-2010 GMC Sierra, Sierra Denali, Yukon, Yukon XL, Yukon Denali, Yukon Denali XL 2008-2010 GMC Savana #08-08-45-004B: Installation of Electrical Aftermarket Accessories-Battery, Ignition and Ground Feeds-Do Not Splice into Wiring Harness (Install Diode to Solenoid/Relay to Suppress Voltage Spikes) - (Nov 17, 2009) This bulletin is being revised to add the 2010 model year and the Express and Savana models. Please discard Corporate Bulletin Number 08-08-45-004A (Section 08 -- Body and Accessories). (continued on next page) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-14 A-14 PAGE Battery/Ignition/Ground Feeds - Installation of Electrical Aftermarket Accessories - Battery, Ignition and Ground Feeds (cont'd) Installation of a Diode to Suppress Voltage Spikes When an electromechanical solenoid or relay is de-energized rapidly by a mechanical switch or semiconductor, the collapsing magnetic field produces a substantial transient voltage in its effort to disperse the stored energy and oppose the sudden change in current flow. These voltage spikes can occur at the positive terminal when the solenoid or relay is de-energized (keyed-off). If a solenoid or relay is wired onto the Run/Crank circuit of the vehicle to control aftermarket equipment, the spikes can be transmitted onto the circuit. The spikes can permanently damage the internal circuitry of the sensitive electronic components and/or control modules that are on this bussed circuit. To prevent damage to these components, the solenoid or relay MUST have the control circuit suppressed with a diode. Install a diode, P/N 12112422, across the coil of the solenoid. It is important that the striped end of the diode be connected to the positive terminal of the coil and the other end of the diode be connected to ground. Install a diode, P/N 12112422, across the coil of the relay. It is important that the striped end of the diode be connected to the positive terminal of the coil and the other end of the diode be connected to ground. Be sure to insulate the diode with heat shrink tubing before installing. There are two different areas on a fullsize truck or utility vehicle that power and grounds can be acquired without having to splice or cut into the existing wiring. One is the MBEC and the other is the UBEC. Important: Be sure to insulate the diode with heat shrink tubing before installing as shown in the picture above. Notice: Some solenoids/relays may only have a positive post and will get their ground through the mounting bracket. In this case, the striped end of the diode is to be connected to the positive terminal and the other end should be connected to the ground of the solenoid/relay. (continued on next page) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-15 A-15 PAGE Battery/Ignition/Ground Feeds - Installation of Electrical Aftermarket Accessories - Battery, Ignition and Ground Feeds (cont'd) MBEC -- Mid-Bussed Electrical Connector The MBEC is located below the instrument panel to the left of the brake pedal (#4 in the graphic points to the MBEC). (continued on next page) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-16 A-16 PAGE Battery/Ignition/Ground Feeds - Installation of Electrical Aftermarket Accessories - Battery, Ignition and Ground Feeds (cont'd) The MBEC has 10 positions for connecting electrical connectors. One of these positions is designated for aftermarket utilization. Install a connector (P/N 20791502) into the open position identified in the following graphic. Within this connector, there is a fused 30 Amp battery feed, a fused 15 Amp battery feed, a fused 10 Amp Run/Crank feed, a 300 milliamp RAP (Retained Accessory Power) feed and a ground. Location of Connector for Aftermarket Utilization: The pin out of the connector is as follows: Important: Connector P/N 20791502 comes with a one wire lead installed. This lead will need to be removed before the connector is pinned for use with aftermarket electrical devices. Cavity Circuit Description Circuit Number Fuse Size 1 Ground 1050 NA 2 Battery Feed 4540 15 Amps 3 Not Used -- -- 4 Not Used -- -- 5 Battery Feed 2340 30 Amps 6 Not Used -- -- 7 Run/Crank Feed 739 10 Amps 8 RAP Feed 43 300 milliamps (continued on next page) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-17 A-17 PAGE Battery/Ignition/Ground Feeds - Installation of Electrical Aftermarket Accessories - Battery, Ignition and Ground Feeds (cont'd) UBEC -- Underhood Bussed Electrical Center On vehicles not equipped with an Auxiliary Battery (Auxiliary Battery RPO TP2), there is a stud that could be used for a fused battery feed at the UBEC. The UBEC is located on the left side of the engine compartment (refer to graphic). Connecting Aftermarket Electrical Devices On Vehicles Not Equipped with TP2: Important: A J-case fuse (1) with a 40 amp maximum rating MUST be inserted into this position (1) for the stud (2) to be powered. Outboard M6 stud (2) can be used for a fused battery feed. Wire Gauge Selection For any of these powered connections to be used, Circuit Protection Guidelines must be followed to assure that the circuit gauge is selected appropriately so that it will be protected by the fuse in case of a short circuit. Parts Information Part Number Description Qty 12112422 Diode 1 Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-18 A-18 PAGE Electrical Charging System Description and Operation ELECTRICAL POWER MANAGEMENT (EPM) OVERVIEW The electrical power management (EPM) system is designed to monitor and control the charging system and send diagnostic messages to alert the driver of possible problems with the battery and generator. This EPM system primarily utilizes existing on-board computer capability to maximize the effectiveness of the generator, to manage the load, improve battery state-of-charge and life, and minimize the system's impact on fuel economy. The EPM system performs 3 functions: • It monitors the battery voltage and estimates the battery condition. • It takes corrective actions by boosting idle speeds, and adjusting the regulated voltage. • It performs diagnostics and driver notification. The battery condition is estimated during ignition-off and during ignition-on. During ignition-off the state-of-charge (SOC) of the battery is determined by measuring the open-circuit voltage. The SOC is a function of the acid concentration and the internal resistance of the battery, and is estimated by reading the battery open circuit voltage when the battery has been at rest for several hours. The SOC can be used as a diagnostic tool to tell the customer or the dealer the condition of the battery. Throughout ignition-on, the algorithm continuously estimates SOC based on adjusted net amp hours, battery capacity, initial SOC, and temperature. While running, the battery degree of discharge is primarily determined by a battery current sensor, which is integrated to obtain net amp hours. In addition, the EPM function is designed to perform regulated voltage control (RVC) to improve battery SOC, battery life, and fuel economy. This is accomplished by using knowledge of the battery SOC and temperature to set the charging voltage to an optimum battery voltage level for recharging without detriment to battery life. The Charging System Description and Operation is divided into 3 sections. The first section describes the charging system components and their integration into the EPM. The second section describes charging system operation. The third section describes the instrument panel cluster (IPC) operation of the charge indicator, driver information center (DIC) messages, and voltmeter operation. (continued on next page) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-19 A-19 PAGE Electrical Charging System Description and Operation (cont'd) CHARGING SYSTEM COMPONENTS Generator The generator is a serviceable component. If there is a diagnosed failure of the generator it must be replaced as an assembly. The engine drive belt drives the generator. When the rotor is spun it induces an alternating current (AC) into the stator windings. The AC voltage is then sent through a series of diodes for rectification. The rectified voltage has been converted into a direct current (DC) for use by the vehicles electrical system to maintain electrical loads and the battery charge. The voltage regulator integral to the generator controls the output of the generator. It is not serviceable. The voltage regulator controls the amount of current provided to the rotor. If the generator has field control circuit failure, the generator defaults to an output voltage of 13.8 volts. Body Control Module (BCM) The body control module (BCM) is a GMLAN device. It communicates with the engine control module (ECM) and the instrument panel cluster (IPC) for electrical power management (EPM) operation. The BCM determines the output of the generator and sends the information to the ECM for control of the generator field control circuit. It monitors the generator field duty cycle signal circuit information sent from the ECM for control of the generator. It monitors a battery current sensor, the battery positive voltage circuit, and estimated battery temperature to determine battery state of charge (SOC). The BCM sends idle boost requests to the ECM. Battery Current Sensor The battery current sensor is a serviceable component that is connected to the negative battery cable at the battery. The battery current sensor is a 3-wire hall effect current sensor. The battery current sensor monitors the battery current. It directly inputs to the BCM. It creates a 5 volt pulse width modulation (PWM) signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-95 percent. Between 0-5 percent and 95-100 percent are for diagnostic purposes. Engine Control Module (ECM) The ECM directly controls the generator field control circuit input to the generator. The ECM receives control decisions based on messages from the BCM. It monitors the generators generator field duty cycle signal circuit and sends the information to the BCM. Instrument Panel Cluster (IPC) The IPC provides a means of customer notification in case of a failure and a voltmeter. There are 2 means of notification, a charge indicator and the driver information center (DIC) SERVICE BATTERY CHARGING SYSTEM message. (continued on next page) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-20 A-20 PAGE Electrical Charging System Description and Operation (cont'd) CHARGING SYSTEM OPERATION The purpose of the charging system is to maintain the battery charge and vehicle loads. There are 6 modes of operation and they include: • Battery Sulfation Mode • Charge Mode • Fuel Economy Mode • Headlamp Mode • Start Up Mode • Voltage Reduction Mode The engine control module (ECM) controls the generator through the generator turn on signal. It monitors the generator performance though the generator field duty cycle signal circuit. The signal is a 5 volt pulse width modulation (PWM) signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-95 percent. Between 0-5 percent and 95-100 percent are for diagnostic purposes. The following table shows the commanded duty cycle and output voltage of the generator: The generator provides a feedback signal of the generator voltage output through the generator field duty cycle signal circuit to the ECM. This information is sent to the body control module (BCM). The signal is a 5 volt PWM signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-99 percent. Between 0-5 percent and 100 percent are for diagnostic purposes. Battery Sulfation Mode The BCM will enter this mode when the interpreted generator output voltage is less than 13.2 volts for 45 minutes. When this condition exists the BCM will enter Charge Mode for 2-3 minutes. The BCM will then determine which mode to enter depending on voltage requirements. Commanded Duty Cycle Generator Output Voltage 10% 11 V 20% 11.56 V 30% 12.12 V 40% 12.68 V 50% 13.25 V 60% 13.81 V 70% 14.37 V 80% 14.94 V 90% 15.5 V (continued on next page) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-21 A-21 PAGE Electrical Charging System Description and Operation (cont'd) Charge Mode The BCM will enter Charge Mode when ever one of the following conditions are met. • The wipers are ON for more than 3 seconds. • The GMLAN Climate Control Voltage Boost Mode Request is true, as sensed by the HVAC control head. High speed cooling fan, rear defogger and HVAC high speed blower operation can cause the BCM to enter the Charge Mode. • The estimated battery temperature is less than 0°C (32°F). • Battery state of charge is less than 80 percent. • Vehicle speed is greater than 145 km/h (90 mph) • Current sensor fault exists • System voltage was determined to be below 12.56 volts • Tow/Haul mode is enabled When any one of these conditions is met, the system will set targeted generator output voltage to a charging voltage between 13.9-15.5 volts, depending on the battery state of charge and estimated battery temperature. Fuel Economy Mode The BCM will enter Fuel Economy Mode when the ambient air temperature is at least 0°C (32°F) but less than or equal to 80°C (176°F), the calculated battery current is less than 15 amps and greater than -8 amps, and the battery state of charge (SOC) is greater than or equal to 80 percent. Its targeted generator output voltage is the open circuit voltage of the battery and can be between 12.5-13.1 volts. The BCM will exit this mode and enter Charge Mode when any of the conditions described above are present. Headlamp Mode The BCM will enter Headlamp Mode when the headlamps are ON. Voltage will be regulated between 13.9-14.5 volts Start Up Mode When the engine is started the BCM sets a targeted generator output voltage of 14.3 volts for 30 seconds. Voltage Reduction Mode The BCM will enter Voltage Reduction Mode when the calculated battery temperature is above 0°C (32°F). The calculated battery current is less than 1 amp and greater than -7 amps, and the generator field duty cycle is less than 99 percent. Its targeted generator output voltage is 13 volts. The BCM will exit this mode once the criteria are met for Charge Mode. (continued on next page) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-22 A-22 PAGE Electrical Charging System Description and Operation (cont'd) Auxiliary Battery Charging (TP2) The auxiliary battery provision (TP2) can be used to supply electrical power to additional equipment that the customer may choose to add, such as a slide-in camper or trailer, without discharging the vehicles primary battery. The auxiliary battery relay closes when the engine is running, in order to allow the generator to charge the auxiliary battery. The relay opens when the engine is off, so that the accessories will not discharge the vehicles primary battery, which is used for engine starting. If the vehicle is equipped with an auxiliary battery, the relay will be located on the driver's side of the vehicle, next to the underhood electrical center. Generally, a fuse should not be used in the STUD 1 Fuse 68 position of the underhood fuse block, if the vehicle is equipped with an auxiliary battery. A plastic plug may be installed in this position instead of a fuse. If a fuse is installed in this position, the accessories will discharge the primary battery in addition to the auxiliary battery. INSTRUMENT PANEL CLUSTER (IPC) OPERATION Charge Indicator Operation The instrument panel cluster (IPC) illuminates the charge indicator and displays a warning message in the driver information center (DIC) when the one or more of the following occurs: • The engine control module (ECM) detects that the generator output is less than 11 volts or greater than 16 volts. The IPC receives a GMLAN message from the ECM requesting illumination. • The BCM determines that the system voltage is less than 11 volts or greater than 16 volts. • The IPC receives a GMLAN message from the body control module (BCM) indicating there is a system voltage range concern. • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds. • The ignition is ON, with the engine OFF. Battery Voltage Gauge Operation The IPC displays the system voltage as received from the BCM over the GMLAN serial data circuit. If there is no communication with the BCM then the gauge will indicate minimum. This vehicle is equipped with a regulated voltage control (RVC) system. This system turns off the generator when it is not required in order to improve fuel economy. The generator will turn back on when additional voltage is required. This will cause the voltmeter to fluctuate between 12 and 14 volts as opposed to non-regulated systems which usually maintain a more consistent reading of 14 volts. This fluctuation with the RVC system is normal system operation and NO repairs should be attempted. Service Battery Charging System The BCM and the ECM will send a GMLAN message to the DIC for the SERVICE BATTERY CHARGING SYSTEM message to be displayed. It is commanded ON when a charging system DTC is a current DTC. The message is turned OFF when the conditions for clearing the DTC have been met. Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-23 A-23 PAGE ELEVATED IDLE / PTO / HIGH IDLE ARE ALL DIFFERENT OPTIONS There have been some questions regarding the differences between Elevated Idle, PTO, and High Idle. The below information is to help provide additional information as to what each of the options are: Elevated Idle Is a standard option on all 6.6L Diesel Engines, which elevates the engine idle speed from base idle to 1050 rpms when outside temperatures are below 32°F (0°C) and the engine coolant temperature is below 150°F (65°C). This feature enhances heater performance by raising the engine coolant temperature faster. It can be turned on or off, please refer to the "Duramax Diesel Supplement" Owner's Manual for more information. PTO (power take-off) Is available as an option (RPO PTO) only on 3500 Chassis Cab models equipped with the 6.6L Diesel Engine RPO LMM and Allison 6-speed transmission RPO MW7. The PTO allows the user to create an auxiliary power source for running add-on equipment, such as salt spreaders, pumps, winches, lift buckets, etc. The dash mounted PTO switch is used to turn on the PTO and controls engine speed to values higher than normal base idle. Refer to UI Bulletins #79 and #80 on our website www.gmupfitter.com. High Idle Is available as an option (RPO UF3) on certain HD models with cruise control. This system can be used to increase your engine idle speed for whatever reason an owner wishes: more generator output at idle, belt driven add on equipment, etc. The cruise control buttons located on the left hand side of the steering wheel are used to operate the High Idle option. If the option was available for your vehicle, and it could have been built with it, you can add it. Check the online order guide to determine if your vehicle could have been built with option UF3. http://eogld.ecomm.gm.com/dmdindex.htm Engine Idle Up (continued on next page) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-24 A-24 PAGE Engine Idle Up (cont'd) ADDING PTO OPTION TO A VEHICLE WITHOUT THE OPTION Condition/Concern: Some owners may request to add the PTO option to their vehicle when it is not equipped with the option. This option is available on 3500 Chassis Cab Models with the 6.6L Diesel engine only. The PTO option is now far more integrated with the vehicle than past models and utilizes the following components: • The body control module (BCM) • The engine control module (ECM) • The instrument panel cluster (IPC) • The PTO gear • The PTO mode select switch • The power take off module (PTOM) • The remote PTO enable switch • The PTO relay • The transmission control module (TCM) Recommendation/Instructions: Due to the PTO's complex integration with the vehicle it is NOT recommended to add this option to any vehicle not already equipped with the OEM PTO option. Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-25 A-25 PAGE Remote Vehicle Immobilizer For applications where it is desirable to leave the vehicle running but assure that it cannot be moved an external +12 v signal can be supplied to the shift interlock solenoid assuring the vehicle will remain in park – see schematic and location drawings. Remote Vehicle Immobilizer Schematic Immobilizer (continued on next page) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-26 A-26 PAGE Immobilizer (cont'd) Remote Vehicle Location Drawing Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-27 A-27 PAGE Forward Lighting - Front of Vehicle Components (X88) (1) Headlamp - Left High Beam (2) Headlamp - Left Low Beam (3) Side Marker Lamp - Left Front (4) Park/Turn Signal Lamp - Left (5) Daytime Running Lamp (DRL) - Left (6) Fog Lamp - Left Front (T96) (7) Daytime Running Lamp (DRL) - Right (8) Park/Turn Signal Lamp - Right (9) Fog Lamp - Right Front (T96) (10) Side Marker Lamp - Right Front (11) Headlamp - Right Low Beam (12) Headlamp - Right High Beam Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-28 A-28 PAGE Forward Lighting - Front of Vehicle Components (Z88) (1) Park/Turn Signal Lamp - Left (2) Side Marker Lamp - Left Front (3) Headlamp - Left (4) Fog Lamp - Left Front (T96) (5) Park/Turn Signal Lamp - Right (6) Headlamp - Right (7) Fog Lamp - Right Front (T96) (8) Side Marker Lamp - Right Front Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-29 A-29 PAGE Forward Lighting - Front of Vehicle Components (Z75) (1) Park Lamp - Left Front (Z75) (2) Repeater Lamp - Left Front (TR2) (3) Side Marker Lamp - Left Front (4) Daytime Running Lamp (DRL) - Left (5) Headlamp - Left (6) Turn Signal Lamp - Left Front (7) Fog Lamp - Left Front (T96) (8) Fog Lamp - Right Front (T96) (9) Turn Signal Lamp - Right Front (10) Side Marker Lamp - Right Front (11) Repeater Lamp - Right Front (TR2) (12) Headlamp - Right (13) Daytime Running Lamp (DRL) - Right (14) Park Lamp - Right Front (Z75) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-30 A-30 PAGE Forward Lighting - Lamp Harness Routing (HP2) (1) Fuse Block - Underhood (2) X100 (X88 or Z75) (3) J160 (4) X101 (5) X106 (6) X104 (7) J101 (8) G101 (9) J162 (10) G100 (11) J161 (12) X103 (13) X105 (T96) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-31 A-31 PAGE Forward Lighting - Lamp Harness Routing (X88) (1) Fuse Block - Underhood (2) X100 (3) X102 (T96) (4) X106 (5) X105 (T96) (6) G101 (7) J101 (8) G100 (9) J100 (10) X103 Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-32 A-32 PAGE Forward Lighting - Lamp Harness Routing (Z75) (1) Fuse Block - Underhood (2) X100 (without EXP)/X140 (EXP) (3) Grille (4) X104 (T96) (5) X106 (without EXP)/X141 (EXP) (6) J103 (7) G101 (8) J101 (9) Horn Relay (VD1) (10) J100 (11) X101 (T96) (12) X103 Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-33 A-33 PAGE Forward Lighting - Lamp Harness Routing (Z88) (1) Fuse Block - Underhood (2) X107 (VYU) (3) X101 (4) X102 (T96) (5) X104 (6) X108 (VYU) (7) G101 (8) J101 (9) G100 (10) J100 (11) X103 Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-34 A-34 PAGE Forward Lighting - Headlamp - Left (T4Q) Connector Part Information Harness: Forward Lamp OEM Connector: 15326939 Service Connector: 88988440 Description: 12-Way F GT 150 280 Series, Sealed (BK) Terminal Part Information Pins: A, F, M Terminated Lead: 13575405 Release Tool: J-38125-553 Diagnostic Test Probe: J-35616-4A (PU) Terminal/Tray: 15304719/19 Core/Insulation Crimp: 2/5 Pins: B-E, L, J Terminated Lead: Pins B, D, E - 13575413 Terminated Lead: Pins C - 13327112 Terminated Lead: Pins L, J - 13327113 Release Tool: J-38125-553 Diagnostic Test Probe: J-35616-2A (GY) Terminal/Tray: 12191819/8 Core/Insulation Crimp: Pins B-E - E/1 Core/Insulation Crimp: Pins L, J - 2/1 Pin Wire Color Circuit No. Function A 1 YE 712 Left Headlamp Low Beam Control B 0.5 L-GN/BK 592 DRL Low Control C 0.35 D-BU 3204 Outage Detection Signal D 0.5 D-BU 545 DRL Control E 0.5 BN 2509 Left Front Park Lamp Control F 1 BK 150 Ground G-H -- -- Not Used J 1 BK 150 Ground K -- -- Not Used L 0.8 D-GN/WH 711 Left Headlamp High Beam Control M 1 BK 150 Ground Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-35 A-35 PAGE Forward Lighting - Headlamp - Left (Z88) Connector Part Information Harness: Forward Lamp OEM Connector: 13511996 Service Connector: 19149288 Description: 3-Way F GT 150 Series, Sealed (GY) Terminal Part Information Terminated Lead: Pins 1, 2 - 13327113 Terminated Lead: Pins 3 - 13575413 Release Tool: J-38125-553 Diagnostic Test Probe: J-35616-2A (GY) Terminal/Tray: 12191819/8 Core/Insulation Crimp: Pins 1, 2 - 2/1 Core/Insulation Crimp: Pins 3 - E/1 Pin Wire Color Circuit No. Function 1 0.8 TN/WH 312 Left Headlamp Low Beam Control 2 1 BK 250 Ground (10 Series) 0.8 BK 250 Ground (20 Series) 0.8 BK 150 Ground (HP2) 3 0.5 L-GN/BK 311 Left Headlamp High Beam Control Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-36 A-36 PAGE Forward Lighting - Headlamp - Left High Beam (X88) Connector Part Information Harness: Left Headlamp OEM Connector: 12059183 Service Connector: 12101898 Description: 2-Way F Metri-Pack 280 Series, Sealed (BK) Terminal Part Information Terminal/Tray: 12077411/2 Core/Insulation Crimp: 2/5 Release Tool/Test Probe: 12094430/J-35616-4A (PU) Pin Wire Color Circuit No. Function A 0.8 BK 150 Ground 0.8 BK 150 Ground B 1 D-GN/WH 711 Left Headlamp High Beam Control Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-37 A-37 PAGE Forward Lighting - Headlamp - Left Low Beam (X88) Connector Part Information Harness: Left Headlamp OEM Connector: 12124819 Service Connector: 12085498 Description: 2-Way F Metri-Pack 280 Series, Sealed (BK) Terminal Part Information Terminal/Tray: Service by Harness - See Part Catalog Core/Insulation Crimp: Not Available Release Tool/Test Probe: Not Available Pin Wire Color Circuit No. Function A 0.8 BK 150 Ground B 1 YE 712 Left Headlamp Low Beam Control Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-38 A-38 PAGE Forward Lighting - Headlamp - Right (T4Q) Connector Part Information Harness: Forward Lamp OEM Connector: 15326939 Service Connector: 88988440 Description: 12-Way F GT 150 280 Series, Sealed (BK) Terminal Part Information Pins: A, F, M, J Terminated Lead: 13575405 Release Tool: J-38125-553 Diagnostic Test Probe: J-35616-4A (PU) Terminal/Tray: 15304719/19 Core/Insulation Crimp: 2/5 Pins: B-E, L Terminated Lead: Pins B, D, E - 13575413 Terminated Lead: Pins C - 13327112 Terminated Lead: Pins L - 13327113 Release Tool: J-38125-553 Diagnostic Test Probe: J-35616-2A (GY) Terminal/Tray: 12191819/8 Core/Insulation Crimp: Pins B-E - E/1 Core/Insulation Crimp: Pins L - 2/1 Pin Wire Color Circuit No. Function A 1 TN/WH 312 Right Headlamp Low Beam Control B 0.5 L-GN/BK 592 DRL Low Control C 0.35 L-BU 3203 Outage Detection Signal D 0.5 D-BU 545 DRL Control E 0.5 BN 2609 Right Front Park Lamp Control F 1 BK 250 Ground G-H -- -- Not Used J 1 BK 250 Ground K -- -- Not Used L 0.8 L-GN/BK 311 Right Headlamp High Beam Control M 1 BK 250 Ground Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-39 A-39 PAGE Forward Lighting - Headlamp - Right (Z88) Connector Part Information Harness: Forward Lamp OEM Connector: 13511996 Service Connector: 19149288 Description: 3-Way F GT 150 Series Sealed (GY) Terminal Part Information Terminated Lead: Pins 1, 2 - 13327113 Terminated Lead: Pins 3 - 13575413 Release Tool: J-38125-553 Diagnostic Test Probe: J-35616-2A (GY) Terminal/Tray: 12191819/8 Core/Insulation Crimp: Pins 1, 2 - 2/1 Core/Insulation Crimp: Pins 3 - E/1 Pin Wire Color Circuit No. Function 1 0.8 TN/WH 312 Right Headlamp Low Beam Control 2 0.8 BK 250 Ground (20 Series) 0.8 BK 150 Ground (10 Series) 3 0.5 L-GN/BK 311 Right Headlamp High Beam Control Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-40 A-40 PAGE Forward Lighting - Headlamp - Right High Beam (X88) Connector Part Information Harness: Right Headlamp OEM Connector: 12059183 Service Connector: 12101898 Description: 2-Way F Metri-Pack 280 Series, Sealed (BK) Terminal Part Information Terminal/Tray: 12077411/2 Core/Insulation Crimp: 2/5 Release Tool/Test Probe: 12094430/J-35616-4A (PU) Pin Wire Color Circuit No. Function A 0.8 BK 150 Ground 0.8 BK 150 Ground B 1 D-GN/WH 311 Right Headlamp High Beam Control Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-41 Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS A-41 PAGE Forward Lighting - Headlamp - Right Low Beam (X88) Connector Part Information Harness: Right Headlamp OEM Connector: 12124819 Service Connector: 12085498 Description: 2-Way F Metri-Pack 280 Series, Sealed (BK) Terminal Part Information Terminal/Tray: Service by Harness - See Part Catalog Core/Insulation Crimp: Not Available Release Tool/Test Probe: Not Available Pin Wire Color Circuit No. Function A 0.8 BK 150 Ground B 1 YE 312 Right Headlamp Low Beam Control Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-42 A-42 PAGE Forward Lighting - Headlamp Replacement (Chevrolet) Preliminary Procedure 1. Remove the upper radiator grille. Refer to Radiator Grille Replacement. 2. Behind the headlamp at the top of the front bumper access the lower inside hidden headlamp bolt. 3. Loosen the bolt only, do not remove, the lower outside hidden headlamp bolt . Callout Component Name/Procedure 1 Headlamp Screws (Qty: 2) Caution: Refer to Fastener Caution in the Preface section. Tighten: 6 N·m (53 lb in) 2 Headlamp Screw (Hidden) Tighten: 6 N·m (53 lb in) 3 Headlamp Housing Support Procedure: 1. Apply masking tape to the front bumper end caps to protect the painted surface. 2. For the right side lamp assembly only, disengage the upper retainer for the radiator air baffle. 3. Release the headlamp from the support tab, rotate the lamp assembly towards the center of the vehicle. 4. Disengage the headlamp electrical connector from the forward lamp harness. Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-43 A-43 PAGE Forward Lighting - Headlamp Replacement (GMC) Preliminary Procedure 1. Remove either the right front or left front wheelhouse liner. Refer to Front Wheelhouse Liner Replacement - Right Side or Front Wheelhouse Liner Replacement - Left Side. 2. Loosen only, do not remove, the lower outside hidden headlamp bolt (2). 3. Depress the housing support tab with a flat-bladed tool downward in order to release the headlamp assembly from the support. 4. Pull the lamp assembly slightly forward to access the electrical connection. 5. Disconnect the forward lamp harness main electrical connector from the headlamp harness. Callout Component Name/Procedure 1 Headlamp Screws (Qty: 2) Caution: Refer to Fastener Caution in the Preface section. Tighten: 6 N·m (53 lb in) 2 Headlamp Screw (Hidden) Tighten: 6 N·m (53 lb in) 3 Headlamp Housing Support Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-44 A-44 PAGE Forward Lighting - Headlamp Replacement (HD Diesel) Preliminary Procedure 1. Lower the front bumper impact bar. Refer to Front Bumper Impact Bar Replacement. 2. Loosen only, do not remove, the lower outside hidden headlamp bolt (2). 3. Depress the housing support tab with a flat-bladed tool downward in order to release the headlamp assembly from the support. 4. Pull the lamp assembly slightly forward to access the electrical connection. 5. Disconnect the forward lamp harness main electrical connector from the headlamp harness. Callout Component Name/Procedure 1 Headlamp Screws (Qty: 2) Caution: Refer to Fastener Caution in the Preface section. Tighten: 6 N·m (53 lb in) 2 Headlamp Screw (Hidden) Tighten: 6 N·m (53 lb in) 3 Headlamp Housing Support Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-45 A-45 PAGE Forward Lighting - Headlamp Bulb Replacement (Chevrolet) Preliminary Procedure 1. Open and support the hood assembly. 2. If replacing the headlamp bulbs on the passenger side, remove the air cleaner box assembly. Refer to Air Cleaner Assembly Replacement. 3. If replacing the headlamp bulbs on the driver side, remove the auxiliary battery, (if equipped). Refer to Auxiliary Battery Replacement. 4. If no auxiliary battery is used, just reach in and access the bulb sockets from inside the engine compartment, disconnect the headlamp bulb electrical connector. 5. Rotate the bulb socket counter-clockwise and remove from the headlamp composite. Callout Component Name/Procedure 1 Headlamp Bulb (Hi) Warning: Refer to Halogen Bulb Warning in the Preface section. Tip: Disconnect the headlamp bulb electrical connector from the headlamp bulb socket assembly. 2 Headlamp Bulb (Lo) Tip: Disconnect the headlamp bulb electrical connector from the headlamp bulb socket assembly. Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-46 A-46 PAGE Forward Lighting - Headlamp Bulb Replacement (GMC) Preliminary Procedure 1. Open and support the hood assembly. 2. If replacing the headlamp bulbs on the passenger side, remove the air cleaner box assembly. Refer to Air Cleaner Assembly Replacement. 3. If replacing the headlamp bulbs on the driver side, remove the auxiliary battery, (if equipped). Refer to Auxiliary Battery Replacement. 4. If no auxiliary battery is used, just reach in and access the bulb sockets from inside the engine compartment, disconnect the headlamp bulb electrical connector. 5. Rotate the bulb socket counter-clockwise and remove from the headlamp composite. Callout Component Name/Procedure 1 Headlamp Bulb (Hi) Warning: Refer to Halogen Bulb Warning in the Preface section. Tip: Disconnect the headlamp bulb electrical connector from the headlamp bulb socket assembly. 2 Headlamp Bulb (Lo) Tip: Disconnect the headlamp bulb electrical connector from the headlamp bulb socket assembly. Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-47 A-47 PAGE Bulb Replacement Replacement Bulbs Chevrolet Silverado Exterior Lamp Bulb Number Back-up Lamp 921LL Back-up Lamp* 1156 Cargo Lamp and Center High-Mounted Stoplamp (CHMSL) 912LL Fender Marker Lamp (If Equipped) W5WLL High-Beam Headlamp 9005 Low-Beam Headlamp H11 License Plate Lamp 168 Sidemarker Lamp/Stoplamp/Taillamp/Turn Signal Lamp 3047K Stoplamp/Turn Signal Lamp/Taillamp* 1157 * Chassis Cab Models Replacement Bulbs GMC Sierra Exterior Lamp Bulb Number Back-up Lamp 921 Back-up Lamp* 1156 Cargo Lamp and Center High-Mounted Stoplamp (CHMSL) 912 Fender Marker W5WLL High-Beam Headlamp 9005 Low-Beam Headlamp H11 License Plate Lamp 168 Stoplamp/Taillamp/Turn Signal Lamp 3047K Sidemarker Lamp 194 Stoplamp/Turn Signal Lamp/Taillamp* 1157 * Chassis Cab Models Replacement Bulbs Chevrolet Tahoe/Suburban If the vehicle is a hybrid, see the hybrid supplement for more information. Exterior Lamp Bulb Number Back-up Lamp 7441 License Plate Lamp W5WLL Rear Turn Signal Lamp, Taillamp, and Stoplamp 3057K Side Marker Lamp 194 Replacement Bulbs Yukon If the vehicle is a hybrid, see the hybrid supplement for more information. Exterior Lamp Bulb Number Back-up Lamp 7441 License Plate Lamp W5WLL Rear Turn Signal Lamp, Taillamp, and Stoplamp 7443 For replacement bulbs not listed here, contact your dealer. Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks Revision date 08/15/2012 Electrical Manual – 2013 Light Duty Full Size C/K Trucks PAGE A-48 A-48 PAGE Rearward Lighting - Separate Stop and Turn Signals 1. Before you start, disconnect the rear chassis lighting connector and select L or R turn signal with the key on. If it fast flashes you will need to assure your BCM is programmed for ZW9 LED compatible rear lamps so the removal of the rear circuit loads will not result in fast flashing. See UI Bulletin 81. If you don't want to reprogram you will need to use ballast resistors in place of the rear turn/stop lamps and run new wires for left, right and stop rear lights. 2. Locate the orange blunt cut wire under the LH dash panel [see: BBM Installing Electric Trailer Brake Controller Wiring.] See the Stop Signal Controls and CHMSL Schematic on the following page. 3. For the LH rear turn signal, cut the Yellow 18 circuit in the BCM connector X5 cavity 1 and splice the harness lead to the light blue white 1314 circuit in the BCM connector X5 cavity 4. See attached schematics Turn Signal Controls and Front Turn Lamp, and Rear Stop Turn Signal Lamps, for details. 4. For the RH rear turn signal, cut the Dark Green 19 circuit in the BCM connector X5 cavity 2 and splice the harness lead to the dark blue white 1315 circuit in the BCM connector X4 cavity 5. 5. The current limit is 6A. If your lamps require more current you must use a relay energized by the front turn signal circuits and switch battery power directly to the rear lamps. (continued on next page) Electrical Manual – 2012 Light Duty Full Size C/K Trucks ELECTRICAL MANUAL – 2012 LIGHT DUTY FULL SIZE C/K TRUCKS Electrical Manual – 2013 Light Duty Full Size C/K Trucks