Chevrolet K1500 2014, C1500 2014, K30 2014 User Manual
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 1
Contents
Document Use and Disclaimers ....................................................................................................................................................................................................... 12
Section A .......................................................................................................................................................................................................................................... 13
Body Control System Description and Operation ........................................................................................................................................................................ 13
Power Mode Master ................................................................................................................................................................................................................ 13
Gateway ................................................................................................................................................................................................................................... 13
Body Control ............................................................................................................................................................................................................................ 13
Power Mode Description and Operation ..................................................................................................................................................................................... 14
Serial Data Power Mode Master .............................................................................................................................................................................................. 14
Relay Controlled Power Mode ................................................................................................................................................................................................. 15
Battery Saver Mode (Transport Mode) ................................................................................................................................................................................... 15
BCM Awake/Sleep States ......................................................................................................................................................................................................... 15
Retained Accessory Power .......................................................................................................................................................................................................... 17
RAP Description and Operation ............................................................................................................................................................................................... 17
Relay Controlled Retained Accessory Power ........................................................................................................................................................................... 17
Serial Data Controlled Retained Accessory Power .................................................................................................................................................................. 18
Back-up Alarm and Camera ......................................................................................................................................................................................................... 19
Back-up Alarm and Camera relay installation schematic ........................................................................................................................................................ 20
Back-up Alarm, Camera and Lamps schematic ........................................................................................................................................................................ 21
Chassis Harness Routing .............................................................................................................................................................................................................. 22
Charging System Description of Operation ................................................................................................................................................................................. 23
Electrical Power Management Overview ................................................................................................................................................................................ 23
Charging System .......................................................................................................................................................................................................................... 24
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 2
Charging System Components ................................................................................................................................................................................................. 24
Charge Mode ........................................................................................................................................................................................................................... 27
Fuel Economy Mode ................................................................................................................................................................................................................ 27
Headlamp Mode ...................................................................................................................................................................................................................... 27
Start Up Mode ......................................................................................................................................................................................................................... 27
Voltage Reduction Mode ......................................................................................................................................................................................................... 28
Instrument Panel Cluster Operation ............................................................................................................................................................................................ 28
Charge Indicator Operation ..................................................................................................................................................................................................... 28
Display Message: ..................................................................................................................................................................................................................... 28
Charging System schematic ......................................................................................................................................................................................................... 29
Engine Idle Up .............................................................................................................................................................................................................................. 30
Elevated Idle ............................................................................................................................................................................................................................ 30
High Idle ................................................................................................................................................................................................................................... 30
PTO (power take-off) ............................................................................................................................................................................................................... 30
Vehicle Regular Production Option (RPO) Content ................................................................................................................................................................. 30
ADDING PTO OPTION TO A VEHICLE WITHOUT THE OPTION .................................................................................................................................................. 31
Installation of Electrical Aftermarket Accessories ...................................................................................................................................................................... 32
Installation of a Diode to Suppress Voltage Spikes ................................................................................................................................................................. 32
Remote Vehicle Immobilizer ........................................................................................................................................................................................................ 33
Exterior Lighting Systems Description and Operation ................................................................................................................................................................. 34
Low Beam Headlamps ............................................................................................................................................................................................................. 34
Run Up Of the Lamp................................................................................................................................................................................................................. 36
When to Change the HID Bulb ................................................................................................................................................................................................. 36
Light Color ................................................................................................................................................................................................................................ 37
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 3
High Beam Headlamps ............................................................................................................................................................................................................. 37
Adaptive Forward Lighting (AFL) .............................................................................................................................................................................................. 37
Automatic Headlamp Leveling ................................................................................................................................................................................................. 38
Daytime Running Lamps (DRL)................................................................................................................................................................................................. 39
Automatic Lamp Control .......................................................................................................................................................................................................... 39
Flash to Pass (FTP) ................................................................................................................................................................................................................... 40
Hazard Lamps ........................................................................................................................................................................................................................... 40
Park, Tail, and License Lamps .................................................................................................................................................................................................. 40
Stop Lamps ............................................................................................................................................................................................................................... 40
Turn Signal Lamps .................................................................................................................................................................................................................... 41
Backup Lamps .......................................................................................................................................................................................................................... 41
Battery Run Down Protection/Inadvertent Power .................................................................................................................................................................. 41
X110 Left Forward Lamp Harness to Headlamp - Connector End View and Pin-out .................................................................................................................. 42
X120 Right Forward Lamp Harness to Headlamp – Connector End View and Pin-out................................................................................................................ 44
Headlamp Replacement .............................................................................................................................................................................................................. 46
Under hood Harness Routing ...................................................................................................................................................................................................... 47
Tail lamp Replacement ................................................................................................................................................................................................................ 47
Chassis Harness Routing .............................................................................................................................................................................................................. 49
Rear Body Junction Block X63A –Connector X5........................................................................................................................................................................... 50
Rear Body Junction Block X63A –Connector X1........................................................................................................................................................................... 51
X63A Junction Block - Rear Body X1 Pin-outs .............................................................................................................................................................................. 52
Bulb Replacement ........................................................................................................................................................................................................................ 54
Rearward Lighting Separate Stop and Turn ................................................................................................................................................................................. 55
Rearward Lighting Separate Stop and Turn (continued) ............................................................................................................................................................. 56
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 4
Dome/Courtesy Lamps (-E29), DH6 ............................................................................................................................................................................................. 57
Dome/Courtesy Lamps E29 ......................................................................................................................................................................................................... 58
Roof Mounted Beacon ................................................................................................................................................................................................................. 59
Park Neutral Signal-Shift Lock Control ......................................................................................................................................................................................... 60
Shift Lock Control Schematic ....................................................................................................................................................................................................... 61
Trailer Brake Control System ....................................................................................................................................................................................................... 62
The Trailer Brake Control System is compatible with two types of Trailer Brake Systems as listed below: ........................................................................... 62
Trailer Brake Output versus Trailer Brake Type ....................................................................................................................................................................... 62
The vehicle is equipped with the following trailer braking components: ............................................................................................................................... 63
Chassis Control Module ........................................................................................................................................................................................................... 63
Trailer Brake Power Control Module ....................................................................................................................................................................................... 64
Trailer Brake Control Panel ...................................................................................................................................................................................................... 64
Trailer Gain Adjustment ........................................................................................................................................................................................................... 64
Trailer Gain Adjustment Procedure ......................................................................................................................................................................................... 65
Hill Start Assist ......................................................................................................................................................................................................................... 65
Trailer Sway Control ................................................................................................................................................................................................................. 65
Driver Information Center Indicators and Messages (Trailer Brake System) .............................................................................................................................. 66
Trailer Connected .................................................................................................................................................................................................................... 66
Check Trailer Wiring ................................................................................................................................................................................................................. 66
Service Trailer Brake System .................................................................................................................................................................................................... 67
Trailer Gain and Output Display .............................................................................................................................................................................................. 67
Trailer Brake Control System Schematic...................................................................................................................................................................................... 68
Chassis Control Module Connector ............................................................................................................................................................................................. 69
Trailer Connector 1 of 3 (Terminals A, B, D, E, F & G) ................................................................................................................................................................. 70
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 5
Trailer Connector 2 of 3 (Terminal C except E29) ........................................................................................................................................................................ 71
Trailer Connector 3 of 3 (Terminal C with E29) ........................................................................................................................................................................... 72
Trailer Connector Location .......................................................................................................................................................................................................... 73
Trailer Connector Pin Out ............................................................................................................................................................................................................ 74
Section B .......................................................................................................................................................................................................................................... 75
Understanding the Alpha Numeric Naming Convention ............................................................................................................................................................. 75
Fuse, Relay, and Block Names ................................................................................................................................................................................................. 75
Battery Fuse Block –Top View ..................................................................................................................................................................................................... 76
Fuse Block (X50) Under-hood - Label........................................................................................................................................................................................... 77
Fuse Block (X50) Under-hood - Top View .................................................................................................................................................................................... 78
Fuse Block (X50) Under-hood - Bottom View .............................................................................................................................................................................. 79
Fuse Block (X50A) Under-hood - Connector X1 ........................................................................................................................................................................... 86
Fuse Block (X50A) Under-hood - Connector X2 ........................................................................................................................................................................... 88
Fuse Block (X50A) Under-hood - Connector X3 ........................................................................................................................................................................... 90
Fuse Block (X50A) Under-hood - Connector X4 ........................................................................................................................................................................... 92
Fuse Block (X50A) Under-hood - Connector X5 ........................................................................................................................................................................... 94
Fuse Block (X51L) Instrument Panel Left - Label.......................................................................................................................................................................... 96
Fuse Block (X51L) Instrument Panel Left - Top View ................................................................................................................................................................... 97
Fuse Block (X51L) Instrument Panel Left - Bottom View ............................................................................................................................................................. 98
Fuse Block (X51L) Instrument Panel Left – Connector X1 ........................................................................................................................................................... 99
Fuse Block (X51L) Instrument Panel Left – Connector X1 Pin-out ............................................................................................................................................. 100
Fuse Block (X51L) Instrument Panel Left – Connector X2 ......................................................................................................................................................... 102
Fuse Block (X51L) Instrument Panel Left – Connector X2 Pin-out ............................................................................................................................................. 103
Fuse Block (X51L) Instrument Panel Left – Connector X3 ......................................................................................................................................................... 105
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 6
Fuse Block (X51L) Instrument Panel – Connector X3 Pin-out .................................................................................................................................................... 106
Fuse Block (X51R) Instrument Panel Right - Label ..................................................................................................................................................................... 107
Fuse Block (X51R) Instrument Panel Right - Top View .............................................................................................................................................................. 108
Fuse Block (X51R) Instrument Panel – Bottom View ................................................................................................................................................................. 109
Fuse Block (X51R) Instrument Panel - Connector X1 ................................................................................................................................................................. 110
Fuse Block (X51R) Instrument Panel - Connector X1 Pin-outs ................................................................................................................................................... 111
Fuse Block (X51R) Instrument Panel - Connector X2 ................................................................................................................................................................. 113
Fuse Block (X51R) Instrument Panel - Connector X2 Pin-outs ................................................................................................................................................... 114
Fuse Block (X51R) Instrument Panel - Connector X3 ................................................................................................................................................................. 116
Fuse Block (X51R) Instrument Panel - Connector X3 Pin-outs ................................................................................................................................................... 117
Junction Block (X61) Instrument Panel – Top View ................................................................................................................................................................... 118
Junction Block (X61) Instrument Panel – Bottom View ............................................................................................................................................................. 119
Junction Block (X61) Instrument Panel – Connector X1 ............................................................................................................................................................ 119
Junction Block (X61) Instrument Panel – Connector X1 Pin-outs .............................................................................................................................................. 121
Junction Block (X61) Instrument Panel – Connector X2 ............................................................................................................................................................ 123
Junction Block (X61) Instrument Panel – Connector X3 ............................................................................................................................................................ 126
Junction Block (X61) Instrument Panel – Connector X3 Pin-outs .............................................................................................................................................. 127
Junction Block (X61) Instrument Panel – Connector X4 ............................................................................................................................................................ 129
Junction Block (X61) Instrument Panel – Connector X4 Pin-outs .............................................................................................................................................. 129
Junction Block (X61) Instrument Panel – Connector X5 ............................................................................................................................................................ 132
Junction Block (X61) Instrument Panel – Connector X5 Pin-outs .............................................................................................................................................. 133
Junction Block (X61) Instrument Panel – Connector X6 ............................................................................................................................................................ 135
Junction Block (X61) Instrument Panel – Connector X6 Pin-outs .............................................................................................................................................. 135
Junction Block (X61) Instrument Panel – Connector X7 ............................................................................................................................................................ 136
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 7
Junction Block (X61) Instrument Panel – Connector X7 Pin-outs .............................................................................................................................................. 137
Junction Block (X61) Instrument Panel – Connector X8 ............................................................................................................................................................ 138
Junction Block (X61) Instrument Panel – Connector X8 Pin-outs .............................................................................................................................................. 139
Junction Block (X61) Instrument Panel – Connector X9 ............................................................................................................................................................ 140
Junction Block (X61) Instrument Panel – Connector X9 Pin-outs .............................................................................................................................................. 140
Section C......................................................................................................................................................................................................................................... 143
K9 Body Control Module ............................................................................................................................................................................................................ 143
K9 Body Control Module (BCM) – Connector X1 ................................................................................................................................................................... 143
K9 Body Control Module (BCM) – Connector X1 Pin-outs ..................................................................................................................................................... 144
K9 Body Control Module (BCM) – Connector X2 ................................................................................................................................................................... 146
K9 Body Control Module (BCM) – Connector X2 Pin-outs ..................................................................................................................................................... 147
K9 Body Control Module (BCM) – Connector X4 ................................................................................................................................................................... 149
K9 Body Control Module (BCM) – Connector X4 Pin-outs ..................................................................................................................................................... 150
K9 Body Control Module (BCM) – Connector X5 ................................................................................................................................................................... 152
K9 Body Control Module (BCM) – Connector X5 Pin-outs ..................................................................................................................................................... 153
Component Locations ................................................................................................................................................................................................................ 177
Front of Vehicle - Chevrolet ................................................................................................................................................................................................... 177
Front of Vehicle - GMC .......................................................................................................................................................................................................... 178
Right Side of Engine Compartment Components .................................................................................................................................................................. 179
Left Side of Engine Compartment Components .................................................................................................................................................................... 179
Underside of Engine Compartment & Cooling Fans .............................................................................................................................................................. 180
Engine Component Views (Top & Left Front) ........................................................................................................................................................................ 181
Engine Component Views (Right Rear, Manual Transmission & Transfer Case) ................................................................................................................... 182
Section D ........................................................................................................................................................................................................................................ 183
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 8
Electrical System - Vehicle Zoning Strategy ............................................................................................................................................................................... 183
Adjustable Pedals (With A45) .................................................................................................................................................................................................... 185
Adjustable Pedals (Without A45) ............................................................................................................................................................................................... 186
Fixed and Moveable Windows –Front Doors ............................................................................................................................................................................ 187
Fixed and Moveable Windows – Rear Doors & Rear Sliding Window ....................................................................................................................................... 188
Rear Defogger/Horns ................................................................................................................................................................................................................. 189
Exterior Lighting - Headlights/Daytime Running Lights (DRL) ................................................................................................................................................... 190
Exterior Lighting – Park Lamps and Controls ............................................................................................................................................................................. 191
Exterior Lighting – Outside Mirror Lamps and Controls ............................................................................................................................................................ 192
Exterior Lighting – Turn Signal Lamps ........................................................................................................................................................................................ 193
Exterior Lighting – Fog Lamps and Roof Lighting ....................................................................................................................................................................... 194
Exterior Lighting –Tail lamps ...................................................................................................................................................................................................... 194
Exterior Lighting – CHMSL and License Plate lamps .................................................................................................................................................................. 196
Interior Lighting – Controls (DD7) .............................................................................................................................................................................................. 197
Interior Lighting – Front Dome Lamps (-E29), DH6 ................................................................................................................................................................... 198
Interior Lighting – Front Dome Lamps (E29) .............................................................................................................................................................................. 199
Interior Lighting – Accent Lamps ............................................................................................................................................................................................... 200
Interior Lighting – Dimming (1 of 3) .......................................................................................................................................................................................... 201
Interior Lighting – Dimming (2 of 3) .......................................................................................................................................................................................... 202
Interior Lighting – Dimming (3 of 3) .......................................................................................................................................................................................... 203
Mirrors – Inside Rearview (DD8) ............................................................................................................................................................................................... 204
Mirrors – Outside Rearview Driver (with A45) .......................................................................................................................................................................... 205
Mirrors – Outside Rearview Passenger (with A45) .................................................................................................................................................................... 206
Mirrors – Outside Rearview Position Controls (without A45) ................................................................................................................................................... 207
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 9
Mirrors – Outside Rearview Heat (DL8, DL3 or DPN) ................................................................................................................................................................ 208
Vehicle Access - Front Switches and Indicators (1 of 2) ............................................................................................................................................................ 209
Vehicle Access - Front Switches and Indicators (2 of 2) ............................................................................................................................................................ 210
Vehicle Access - Rear Switches and Indicators .......................................................................................................................................................................... 211
Vehicle Access – Actuators ........................................................................................................................................................................................................ 212
Wipers and Washers – Controls ................................................................................................................................................................................................ 213
Wipers and Washers – Motor and Washers .............................................................................................................................................................................. 214
Cigar Lighter/Power Outlets – 12V DC ....................................................................................................................................................................................... 215
Cigar Lighter/Power Outlets – 110V AC ..................................................................................................................................................................................... 216
Cigar Lighter/Power Outlets – 220V AC ..................................................................................................................................................................................... 217
Power Moding Schematics - Ignition Off, Ignition I and Retained Accessory ............................................................................................................................ 218
Power Moding Schematics - Ignition II and Ignition III .............................................................................................................................................................. 219
Power Distribution Schematics - X50D Fuse Block - Battery ..................................................................................................................................................... 220
Power Distribution Schematics X50A Fuse Block – Under-hood Bussing .................................................................................................................................. 221
Power Distribution Schematics - F1UA, F2UA, F11UA, F12UA, F18UA, F20UA and F54UA ...................................................................................................... 222
Power Distribution Schematics - 4WD Fuse, F9UA, F35UA, F47UA and F53UA ........................................................................................................................ 223
Power Distribution Schematics - F14UA, F27UA and F57UA ..................................................................................................................................................... 224
Power Distribution Schematics - F13UA, F16U and F28UA ....................................................................................................................................................... 225
Power Distribution Schematics - F15UA, F32UA, F37UA and F48UA ........................................................................................................................................ 226
Power Distribution Schematics - F33UA, F39UA and F49UA ..................................................................................................................................................... 227
Power Distribution Schematics - F42UA, F44UA, F45UA and F50UA ........................................................................................................................................ 228
Power Distribution Schematics - F43UA .................................................................................................................................................................................... 229
Power Distribution Schematics - F3UA, F4UA, F7UA, F24UA and F56UA ................................................................................................................................. 230
Power Distribution Schematics - X51L Fuse Block - Instrument Panel Left Bussing .................................................................................................................. 231
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 10
Power Distribution Schematics - F6DL, F7DL, F9DL, F17DL, F25DL, F26DL, F34DL and F44DL ................................................................................................. 232
Power Distribution Schematics - F22DL, F23DL, F30DL, F31DL and F32DL ............................................................................................................................... 233
Power Distribution Schematics - F1DL, F2DL, F3DL, F10DL, F11DL, F12DL, F13DL, F40DL and F41DL...................................................................................... 234
Power Distribution Schematics - X51R Fuse Block - Instrument Panel Right Bussing ............................................................................................................... 235
Power Distribution Schematics - F7DR, F22DR, F31DR, F41DR, F44DR and F46DR .................................................................................................................. 236
Power Distribution Schematics - F18DR, F25DR and F38DR ..................................................................................................................................................... 237
Power Distribution Schematics - F6DR, F8DR, F27DR, F34DR, F35DR, F42DR and F43DR ........................................................................................................ 238
Ground Distribution Schematics - G101 and G102 .................................................................................................................................................................... 239
Ground Distribution Schematics - G108, G130, G140 and G327 ............................................................................................................................................... 240
Ground Distribution Schematics - G110 .................................................................................................................................................................................... 241
Ground Distribution Schematics - G121 and G400 .................................................................................................................................................................... 242
Ground Distribution Schematics - G210 (1 of 2) ........................................................................................................................................................................ 243
Ground Distribution Schematics - G210 (2 of 2) ........................................................................................................................................................................ 244
Ground Distribution Schematics - G218 (except E29) ............................................................................................................................................................... 245
Ground Distribution Schematics - G218 (E29) ........................................................................................................................................................................... 246
Ground Distribution Schematics - G311 .................................................................................................................................................................................... 247
Ground Distribution Schematics - G312 .................................................................................................................................................................................... 248
Ground Distribution Schematics - G325 .................................................................................................................................................................................... 249
Ground Location Views – G101 ................................................................................................................................................................................................. 250
Ground Location Views G102 .................................................................................................................................................................................................... 251
Ground Location Views G110 .................................................................................................................................................................................................... 252
Ground Location Views G120 .................................................................................................................................................................................................... 253
Ground Location Views G121 and G400 .................................................................................................................................................................................... 254
Ground Location Views G130 .................................................................................................................................................................................................... 255
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 11
Ground Location Views G140 .................................................................................................................................................................................................... 256
Ground Location Views G210 and G218 .................................................................................................................................................................................... 257
Ground Location Views G311 and G325 .................................................................................................................................................................................... 258
Ground Location Views G312 and G327 .................................................................................................................................................................................... 259
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 12
Document Use and Disclaimers
GM Upfitter Integration Body Builder Manuals and Technical Bulletins are intended for use by professional technicians,
NOT a "do-it-yourselfer". They are written to inform technicians of conditions that may occur on some vehicles and/or
models, or to provide information that could assist in the proper service and/or modification of a vehicle. Properly
trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a
condition is described, DO NOT assume that the bulletin applies to the vehicle and/or model, Also do NOT assume that
every vehicle and/or model will have that condition.
Contact GM Upfitter Integration for information on whether the information is applicable your vehicle.
GM Upfitter Integration does not take responsibility for nor approve alterations to GM Commercial Chassis, Pickup &
Utility Vehicles.
If an Upfitter or Second Stage Manufacturer (SSM) or Individual chooses to modify a GM Chassis/Vehicle and/or its
components, liability and possible recertification responsibility for compliance with all related FMVSS/CMVSS and
regional standards lies with the Upfitter/SSM or Individual.
In addition liability for Non-OEM (aftermarket) installed components used in modifications to a GM Chassis/Vehicle
and/or its components is solely with the responsible aftermarket component manufacturer and the installer. If an
Upfitter/SSM or Individual chooses to modify a GM part/s design or function they risk voiding the GM warranty and
assume liability for the modification
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 13
Section A
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 high speed GMLAN serial data bus, low speed GMLAN serial data bus and Multiple LIN buses and acts as a
gateway between them.
Power Mode Master
This vehicle body control module (BCM) functions as the power mode master (PMM). The ignition switch is a low current switch with
multiple discrete ignition switch signals to the PMM for determining the power mode that will be sent over the serial data circuits to the
other modules that need this information; the PMM will activate relays and other direct outputs of the PMM as needed. Refer to Power
Mode Description and Operation for a complete description of power mode functions.
Gateway
The body control module (BCM) in this vehicle functions as a gateway or translator. The purpose of the gateway is to translate serial
data messages between the GMLAN high speed bus and the GMLAN low speed bus for communication between the various modules.
The gateway will interact with each network according to that network's transmission protocol.
All communication between the BCM and a scan tool is on the high speed GMLAN serial data circuits. A lost communication DTC
typically is set in modules other than the module with a communication failure.
Body Control
The various body control module (BCM) input and output circuits are illustrated in the corresponding functional areas on the BCM
electrical schematics. Refer to the Body Control System Schematics for more detailed information.
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 14
Power Mode Parameters
Ignition Switch Position
Power Mode Transmitted
Ign. Off/Run/Crank
(Off/Run Crank 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
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. This vehicles power mode
master is the body control module (BCM). The BCM has multiple B+ circuits that feed into it. Each of those circuits are partitioned within
the controller to drive certain outputs of the vehicle’s body functions. An open or short in any one of the B+ circuits may induce multiple
codes/or a section of non-functionality within the BCM with the rest of the BCM functioning normally. In this case it is useful to refer to
the power distribution schematics to determine if the non-functional partition of the controller shares a common B+ circuit. The ignition
switch is a low current switch with multiple discrete ignition switch signals to the power mode master for determination of the power
mode that will be sent over the serial data circuits to the other modules that need this information. The power mode master will also
activate relays and other direct outputs of the power mode master as needed. The power mode master 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 power mode serial data message does not match what the individual
module can see from its own connections.
The power mode master receives ignition switch signals to identify the operators desired power mode. The Power Mode Parameter
tables below illustrate the correct state of these input parameters (circuits) in correspondence to the ignition switch position:
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 15
Relay Controlled Power Mode
The BCM uses the discrete ignition switch inputs Off/Run/Crank 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 retained accessory power relay 1 and retained accessory power relay 2 remain 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
function.
Battery Saver Mode (Transport Mode)
Battery saver mode (transport mode) reduces the parasitic load of some modules during overseas shipment or during vehicle storage
conditions. This improves the drain time on the battery (up to 70 days without the battery going dead). When a vehicle is in
transport/storage, some features may have reduced functionality while in the battery saver mode, such as disabling keyless entry, afterblow, and content theft features. Battery saver mode is initiated by turning on the hazard flashers, applying the brake pedal, and then
turning the ignition key to the start position or pushing the ignition mode switch with the foot on the brake for greater than 15 seconds.
The mode is disengaged by repeating the previous process. The driver information center (if equipped) will display Transport Mode is On
when battery saver mode is enabled and Transport Mode is Off when battery saver mode is disabled. For vehicles not equipped with a
driver information center, the battery indicator light will constantly flash on the Instrument Cluster when battery saver mode is enabled.
This feature can be used as many times as necessary if the vehicle is to be stored for an extended period of time.
BCM Awake/Sleep States
The 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
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 16
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.
Ignition OFF, transmitter is out of range
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.
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 17
Retained Accessory Power
RAP Description and Operation
The Body Control Module (BCM) monitors the ignition switch position, battery condition, and each door ajar/open switch status to
determine whether the retained accessory power should be initiated or terminated. Retained accessory power is controlled by two
different methods; relay control and serial data. Some modules receive a retained accessory power message from the BCM over the
serial data circuits. Serial data controlled retained accessory power is deactivated as required by their modules retained accessory
power mode operation. Other subsystems are activated directly by the BCM through a relay. Components and systems that are active in
retained accessory power are also activated anytime the ignition is any position other than OFF regardless of the door switch signals.
Relay Controlled Retained Accessory Power
The BCM keeps the retained accessory power relay 1 and retained accessory power relay 2 energized during all power modes, except
Off-Awake and Crank. The retained accessory power relay 1 and retained accessory power relay 2 are also energized for approximately
10 minutes after shutting the ignition OFF and removing the key, providing no door is opened.
Relay controlled retained accessory power will end when one of the following conditions is met:
The BCM receives an input from any door ajar or open switch indicating the opening of any door after the ignition key is out of
the ignition.
Note: If the BCM is receiving any door ajar or open signal from those switches when the ignition key is turned OFF, retained
accessory power will not initiate.
The BCM internal timer for the retained accessory power expires after approximately 10 minutes.
The BCM detects a decrease in battery capacity below a prescribed limit.
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 18
Relay Controlled Retained Accessory Power (continued)
Systems powered by the retained accessory power relay 1 and retained accessory power relay 2 during the retained accessory power
mode are as follows:
Note: The vehicle may not be equipped with all components as listed below.
Accessory Power Receptacle
Cigarette Lighter Receptacle
Sunroof Control Module
Sunroof Switch
Sliding Rear Window Switch
Mobile Device Wireless Charger Module
Serial Data Controlled Retained Accessory Power
Retained accessory power systems controlled by serial data are as follows:
Radio:
Radio retained accessory power activation / termination is the same as relay operation with one exception; the only door switch that
will turn off the radio during retained accessory power is the driver door open switch.
Vehicle Communication Interface Module (VCIM) (Onstar®) (If Equipped)
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.
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 19
Back-up Alarm and Camera
For installation of a Back-up Alarm/Camera on vehicles not equipped with 8S3 (factory back-up alarm) connections can be made at the rear
body junction block (X63A).
In addition to when the vehicle is operated in reverse, the back-ups are illuminated during a lighted exit and as a key fob acknowledgement.
When using the back –lamps circuit to activate a back-up alarm, in which the perimeter lighting feature is set to ON for exiting, the back-up
alarm will be activated during the exit lighting event. To prevent this undesired alarm (or camera) activation during the exit lighting mode use
one of the two options listed below…
1. Have the vehicle’ BCM (Body Control Module) reprogramming with a new calibration that includes RPO (regular production Option)
code SFW. This option will suppress the activation of the Back-up lamps during the exit lighting mode operation.
OR
2. Install an ignition controlled relay to which only allows for the Back-up lamp signal to be provided to the alarm/camera if the ignition
is in the “RUN” mode, and the vehicle is being operated in reverse mode. (see sample schematic)
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 20
BACKUP LAMP WIRE
BACKUP ALARM
Relay
Ground
Back-up Alarm and Camera relay installation schematic
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 21
Back-up Alarm, Camera and Lamps schematic
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 22
Chassis Harness Routing
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 23
Charging System Description of Operation
Electrical Power Management Overview
The electrical power management 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 electrical power management system primarily utilizes existing onboard 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 electrical power management 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 of the battery is
determined by measuring the open-circuit voltage. The state-of-charge 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 state-of-charge 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 state-of-charge based on adjusted net amp hours, battery capacity, initial state-of-charge, 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 electrical power management function is designed to perform regulated voltage control to improve battery state-ofcharge, battery life, and fuel economy. This is accomplished by using knowledge of the battery state-of-charge and temperature to set the
charging voltage to an optimum battery voltage level for recharging without detriment to battery life.
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 24
Charging System
The Charging System Description and Operation is divided into 3 sections. The first section describes the charging system components and
their integration into the electrical power management. The second section describes charging system operation. The third section
describes the instrument panel cluster operation of the charge indicator, driver information center messages, and voltmeter operation.
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 V.
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 for electrical power management (electrical power management) operation. The BCM determines the output of the generator and
sends the information to the ECM for control of the generator turn on signal 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. The BCM performs idle boost.
Battery Current Sensor
The battery current sensor is a serviceable component that is connected to either the negative or positive 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.
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 25
Engine Control Module (ECM)
When the engine is running, the generator turn-on signal is sent to the generator from the ECM, turning on the regulator. The generator's
voltage regulator controls current to the rotor, thereby controlling the output voltage. The rotor current is proportional to the electrical
pulse width supplied by the regulator. When the engine is started, the regulator senses generator rotation by detecting AC voltage at the
stator through an internal wire. Once the engine is running, the regulator varies the field current by controlling the pulse width. This
regulates the generator output voltage for proper battery charging and electrical system operation. The generator field duty terminal is
connected internally to the voltage regulator and externally to the ECM. When the voltage regulator detects a charging system problem, it
grounds this circuit to signal the ECM that a problem exists. The ECM monitors the generator field duty cycle signal circuit, and receives
control decisions based on information from the BCM.
Instrument Panel Cluster
The instrument panel cluster provides the customer notification in case a concern with the charging system. There are 2 means of
notification, a charge indicator and a driver information center message of SERVICE BATTERY CHARGING SYSTEM if equipped.
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 circuit. The ECM monitors the generator
performance though the generator field duty cycle signal circuit. The signal is a 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 (see table next page):
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 26
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
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 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 V 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.
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 27
Charge Mode
The BCM will enter Charge Mode whenever one of the following conditions are met.
The wipers are ON for more than 3 seconds.
Climate Control Voltage Boost Mode Request via serial data 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 V
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 V,
depending on the battery state of charge and estimated battery temperature.
Fuel Economy Mode
The BCM will enter Fuel Economy Mode when the estimated battery 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 amperes and greater than −8 amperes, and the battery state-of-charge 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 V. 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 whenever the headlamps are ON (high or low beams). Voltage will be regulated between 13.9–14.5 V.
Start Up Mode
When the engine is started the BCM sets a targeted generator output voltage of 14.5 V for 30 seconds.
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 28
Voltage Reduction Mode
The BCM will enter Voltage Reduction Mode when the calculated ambient air temperature is above 0°C (32°F). The calculated battery
current is less than 1 ampere and greater than −7 amperes, and the generator field duty cycle is less than 99 percent. Its targeted
generator output voltage is 12.9 V. The BCM will exit this mode once the criteria are met for Charge Mode.
Instrument Panel Cluster Operation
Charge Indicator Operation
The instrument panel cluster illuminates the charge indicator and displays a warning message in the driver information center if equipped,
when the one or more of the following occurs:
The engine control module (ECM) detects that the generator output is less than 11 V or greater than 16 V. The instrument panel
cluster receives a serial data message from the ECM requesting illumination.
The instrument panel cluster determines that the system voltage is less than 11 V or greater than 16 V for more than 30 seconds.
The instrument panel cluster receives a GMLAN message from the body control module (BCM) indicating there is a system voltage
range concern.
The instrument panel cluster performs the displays test at the start of each ignition cycle. The indicator illuminates for
approximately 3 seconds.
Display Message:
BATTERY NOT CHARGING SERVICE CHARGING SYSTEM or SERVICE BATTERY CHARGING SYSTEM
The BCM and the ECM will send a serial data message to the driver information center for the BATTERY NOT CHARGING SERVICE
CHARGING SYSTEM or 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-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 29
Charging System schematic
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Electrical Manual-NEW 2014 Light Duty Full Size C/K Trucks Pg. 30
Engine Idle Up
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.
High Idle
An option (RPO UF3) is available 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. For more information see the Owner’s Manual or online
at ″www.gmupfitter.com″.
PTO (power take-off)
An option (RPO PTO) is available only on 3500 Chassis Cab models (31xxx series) equipped with the 6.6L Diesel Engine and Allison 6-speed
transmission. 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. For more information see the ″Duramax Diesel Supplement″ Owner’s Manual or online at ″www.gmupfitter.com″.
Vehicle Regular Production Option (RPO) Content
When attempting to determine a vehicle’s option refer to the vehicle’s SPID (Service Parts IDentfication) label.
Electrical Manual-2014 Light Duty Full Size C/K Trucks Revision Date 06/19/2013 (WIP)
Loading...