Page 538 of 600
Fuses Usage
BODY Harness Connector
DDM Driver Door Module
AUX PWR 2, M/GATE Not Used
LCKS Power Door Lock System
ECC, TPMTire Pressure Monitoring
System
TBC 2C Truck Body Controller
HAZRD Flasher Module
CB LT DRSLeft Power Windows
Circuit Breaker
TBC 2B Truck Body Controller
TBC 2A Truck Body ControllerCenter Instrument Panel Fuse Block
The center instrument panel utility block is located
underneath the instrument panel, to the left of the
steering column.
Device Usage
SEO Special Equipment Option
TRAILER Trailer Brake Wiring
UPFIT Up tter (Not Used)
5-126
Page 539 of 600
Device Usage
SL RIDERide Control Harness
Connection
HDLR 2 Headliner Wiring Connector
BODY Body Wiring Connector
DEFOG Rear Defogger Relay
HDLNR 1 Headliner Wiring Connector 1
SPARE RELAY Not Used
CB SEATDriver and Passenger Seat
Module Circuit Breaker
CB RT DOORRight Power Windows Circuit
Breaker
SPARE Not Used
INFOInfotainment Harness
ConnectionUnderhood Fuse Block
The underhood fuse block in the engine compartment
on the driver’s side of the vehicle near the battery.
Lift the cover for access to the fuse/relay block.
To remove fuses hold the end of the fuse between your
thumb and index nger and pull straight out.
SeeEngine Compartment Overview on page 5-14for
more information on its location.
5-127
Page 541 of 600

*1Fuel Injection Rail #2-Gasoline Engine; Engine
Control Module-Diesel Engine.
*2Fuel Injection Rail #1-Gasoline Engine;
Actuator-Diesel Engine.
*3Oxygen Sensors-Gasoline Engine; Fuel Heater-Diesel
Engine.
*4Oxygen Sensors-Gasoline Engine; Engine Control
Module 1-Diesel Engine.
*5Ignition 1-Gasoline Engine; Engine Control
Module-Diesel Engine.
*6Powertrain Control Module B-Gasoline Engine;
Engine Control Module B-Diesel Engine.
*7Rear Climate Control.
*8Sunroof.
Fuses Usage
GLOW PLUGDiesel Glow Plugs and
Intake Air Heater
CUST FEED Gasoline Accessory Power
HYBRID Hybrid
STUD #1Auxiliary Power (Single
Battery and Diesels Only)/
Dual Battery (TP2) Do not
install fuse.
Fuses Usage
MBECMid Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
BLWR Front Climate Control Fan
LBECLeft Bussed Electrical Center,
Door Modules, Door Locks,
Auxiliary Power Outlet—Rear
Cargo Area and Instrument
Panel
STUD #2*Accessory Power/Trailer
Wiring Brake Feed
ABS Anti-lock Brakes
VSES/ECAS Vehicle Stability
IGN A Ignition Power
IGN B Ignition Power
LBEC 1Left Bussed Electrical Center,
Left Doors, Truck Body
Controller, Flasher Module
TRL PARK Parking Lamps Trailer Wiring
RR PARKRight Rear Parking and
Sidemarker Lamps
5-129
Page 542 of 600
Fuses Usage
LR PARKLeft Rear Parking and
Sidemarker Lamps
PARK LP Parking Lamps Relay
STRTR Starter Relay
INTPARK Interior Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller Battery
Feed
SEO B2 Off-Road Lamps
4WS Not Used
AUX PWRAuxiliary Power Outlet —
Console
PCM 1 Powertrain Control Module
ETC/ECMElectronic Throttle Control,
Electronic Brake
Controller-Gasoline Engine,
Fan Clutch-Diesel Engines
IGN EInstrument Panel Cluster,
Air Conditioning Relay,
Turn Signal/Hazard Switch,
Starter RelayFuses Usage
RTD Ride Control
TRL B/U Backup Lamps Trailer Wiring
F/PMP Fuel Pump (Relay)
B/U LPBack-up Lamps, Automatic
Transmission Shift Lock
Control System
RR DEFOG Rear Window Defogger
HDLP-HI Headlamp High Beam Relay
PRIME Not Used
AIRBAGSupplemental In atable
Restraint System
FRT PARKFront Parking Lamps,
Sidemarker Lamps
DRLDaytime Running Lamps
(Relay)
SEO IGN Rear Defog Relay
TBC IGN1 Truck Body Controller Ignition
HI HDLP-LT High Beam Headlamp-Left
LH HID Not Used
5-130
Page 543 of 600
Fuses Usage
DRL Daytime Running Lamps
RVC Regulated Voltage Control
IPC/DICInstrument Panel
Cluster/Driver Information
Center
HVAC/ECAS Climate Control Controller
CIG LTR Cigarette Lighter
HI HDLP-RT High Beam Headlamp-Right
HDLP-LOW Headlamp Low Beam Relay
A/C COMPAir Conditioning Compressor
Relay
A/C COMP Air Conditioning Compressor
TCMB Transmission Control Module
RR WPR Not Used
RADIO Audio System
SEO B1Mid Bussed Electrical Center,
Rear Heated Seats,
Universal Home Remote
System
LO HDLP-LT Headlamp Low Beam-LeftFuses Usage
BTSIBrake Transmission Shift
Interlock System
CRNK Starting System
LO HDLP-RT Headlamp Low Beam-Right
FOG LP Fog Lamps Relay
FOG LP Fog Lamps
HORN Horn Relay
W/S WASHWindshield Washer Pump
Relay
W/S WASH Windshield Washer Pump
INFOOnStar
®/Rear Seat
Entertainment
RADIO AMP Radio Ampli er
RH HID Not Used
HORN Horn
EAP Not Used
TREC Not Used
SBA Supplemental Brake Assist
5-131
Page 544 of 600
Auxiliary Electric Cooling Fan
Fuse Block
The auxiliary electric
cooling fan fuse block is
located in the engine
compartment on the
driver’s side of the vehicle
next to the underhood
fuse block.
Lift the cover for access to the fuse/relay block.
Fuses Usage
COOL/FAN Cooling Fan
COOL/FAN Cooling Fan Relay Fuse
COOL/FAN Cooling Fan Fuse
Relays Usage
COOL/FAN 1 Cooling Fan Relay 1
COOL/FAN 3 Cooling Fan Relay 3
COOL/FAN 2 Cooling Fan Relay 2
5-132
Page 591 of 600

E
Electrical System
Add-On Equipment.....................................5-123
Center Instrument Panel Fuse Block.............5-126
Fuses and Circuit Breakers.........................5-123
Instrument Panel Fuse Block.......................5-124
Power Windows and Other Power Options....5-123
Underhood Fuse Block...............................5-127
Windshield Wiper Fuses.............................5-123
Engine
Air Cleaner/Filter.........................................5-25
Battery.......................................................5-51
Check and Service Engine Soon Light............3-46
Coolant......................................................5-35
Coolant Heater............................................2-25
Coolant Temperature Gage...........................3-43
Drive Belt Routing.......................................6-19
Engine Compartment Overview......................5-14
Exhaust.....................................................2-57
Fan Noise..................................................5-45
Oil .............................................................5-20
Oil Life System...........................................5-23
Overheated Protection Operating Mode...........5-39
Overheating................................................5-37
Starting......................................................2-23Entry Lighting.................................................3-19
Event Data Recorders (EDR)............................. 7-9
Exit Lighting...................................................3-19
Extender, Safety Belt.......................................1-30
F
Filter
Engine Air Cleaner......................................5-25
Finish Damage.............................................5-120
Fixed Mast Antenna.......................................3-132
Flash-to-Pass................................................... 3-9
Flat Tire........................................................5-90
Flat Tire, Changing.........................................5-91
Flat Tire, Storing...........................................5-108
Fluid
Automatic Transmission........................5-28, 5-30
Manual Transmission....................................5-33
Power Steering...........................................5-45
Windshield Washer......................................5-46
Fog Lamps....................................................3-17
Four-Wheel Drive....................................2-38, 5-59
Four-Wheel-Drive Light....................................3-50
Front Axle......................................................5-60
Front Reading Lamps......................................3-19
Front Storage Area.........................................2-79
5
Page 592 of 600

Fuel............................................................... 5-5
Additives...................................................... 5-7
California Fuel.............................................. 5-7
E85 (85% Ethanol)........................................ 5-8
Filling a Portable Fuel Container....................5-11
Filling Your Tank..........................................5-10
Fuels in Foreign Countries.............................. 5-9
Gage.........................................................3-51
Gasoline Octane........................................... 5-6
Gasoline Speci cations.................................. 5-6
Low Warning Light.......................................3-51
Fuses
Center Instrument Panel Fuse Block.............5-126
Fuses and Circuit Breakers.........................5-123
Instrument Panel Fuse Block.......................5-124
Underhood Fuse Block...............................5-127
Windshield Wiper.......................................5-123
G
Gage
Engine Coolant Temperature.........................3-43
Fuel..........................................................3-51
Oil Pressure...............................................3-48
Speedometer..............................................3-33
Tachometer.................................................3-34
Transmission Temperature.............................3-44
Voltmeter Gage...........................................3-40
Garage Door Opener.......................................2-75Gasoline
Octane........................................................ 5-6
Speci cations............................................... 5-6
Glove Box.....................................................2-79
GM Mobility Reimbursement Program.................. 7-5
H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-7
Headlamps............................................3-14, 5-63
Automatic Headlamp System.........................3-15
Bulb Replacement.......................................5-63
Daytime Running Lamps...............................3-15
Flash-to-Pass............................................... 3-9
Front Turn Signal, Sidemarker and Daytime
Running Lamps........................................5-64
Halogen Bulbs............................................5-63
High/Low Beam Changer................................ 3-8
On Reminder..............................................3-14
Pickup Box Identi cation and Fender Marker
Lamps....................................................5-68
Roof Marker Lamps.....................................5-66
Heated Seats................................................... 1-5
Heater...................................................3-21, 3-22
Heater...........................................................3-25
Highbeam On Light.........................................3-49
Highway Hypnosis...........................................4-39
Hill and Mountain Roads..................................4-40
6