Page 465 of 552

{CAUTION:
Incorrect wheel nuts or improperly tightened
wheel nuts can cause the wheel to come loose
and even come off. This could lead to an
accident. Be sure to use the correct wheel
nuts. If you have to replace them, be sure to
get new GM original equipment wheel nuts.
Stop somewhere as soon as you can and have
the nuts tightened with a torque wrench to the
proper torque speci®cation. See ªCapacities
and Speci®cationsº in the Index for wheel nut
torque speci®cation.
Notice:Improperly tightened wheel nuts can lead
to brake pulsation and rotor damage. To avoid
expensive brake repairs, evenly tighten the wheel
nuts in the proper sequence and to the proper
torque speci®cation. See ªCapacities and
Speci®cationsº in the index for the wheel nut torque
speci®cation.
When you reinstall the regular wheel and tire, you must
also reinstall the center cap. Place the cap on the wheel
and tap it into place until it seats ¯ush with the wheel. The
cap only goes on one way. Be sure to line up the tab on
the center cap with the indentation on the wheel.
5-89
Page 487 of 552
Fuses Usage
UNLOCKPower Door Lock Relay
(Unlock Function)
RR FOG LP Rear Fog Lamp (Export Only)
BRAKE Anti-Lock Brake System
DRIVER UNLOCKPower Door Lock Relay
(Driver's Door Unlock
Function)
IGN 0 PCM, TCM
TBC IGN 0 Truck Body Controller
VEH CHMSLVehicle and Trailer High
Mounted Stoplamp
LT TRLR ST/TRN Left Turn Signal/Stop Trailer
LT TRNLeft Turn Signals and
Sidemarkers
VEH STOPVehicle Stoplamps, Brake
Module, Electronic Throttle
Control Module
RT TRLR ST/TRN Right Turn Signal/Stop TrailerFuses Usage
RT TRNRight Turn Signals and
Sidemarkers
BODY Harness Connector
DDM Driver Door Module
AUX PWR 2Rear Cargo Area Power
Outlets
LOCKS Power Door Lock System
ECCRear Electronic Climate
Control
TBC 2C Truck Body Controller
FLASH Flasher Module
CB LT DOORSLeft Power Window Circuit
Breaker
TBC 2B Truck Body Controller
TBC 2A Truck Body Controller
5-111
Page 488 of 552
Center 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)
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 Window Circuit
Breaker
SPARE Not Used
INFOInfotainment Harness
Connection
5-112
Page 491 of 552

*1Ð Gasoline Engine and Fuel Injection Rail #2.
*2Ð Gasoline Engine and Fuel Injection Rail #1.
*3Ð Gasoline Engine; Oxygen Sensors.
*4Ð Gasoline Engine; Oxygen Sensors.
*5Ð PCM Ignition
Fuses Usage
GLOW PLUG Not Used
CUST FEED Gasoline Accessory Power
STUD #1Auxiliary Power (Single
Battery and Diesels
Only)/Dual Battery (TP2) Do
not install fuse.
MBECMid Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
BLOWER Front Climate Control Fan
LBECLeft Bussed Electrical Center,
Door Modules, Door Locks,
Auxiliary Power OutletÐRear
Cargo Area and Instrument
Panel
Fuses Usage
STUD 2Accessory 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
LR PARKLeft Rear Parking and
Sidemarker Lamps
PARK LP Parking Lamps Relay
STARTER Starter Relay
INTPARK Interior Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller
Battery Feed
5-115
Page 492 of 552

Fuses Usage
SUNROOF Sunroof
SEO B2 Off-Road Lamps
4WSVent Solenoid
Canister/Quadrasteer Module
Power
RR HVAC Rear Climate Control
AUX PWRAuxiliary Power Outlet Ð
Console
IGN 1 Ignition Relay
PCM 1 Powertrain Control Module
ETC/ECMElectronic Throttle Control,
Electronic Brake Controller
IGN EInstrument Panel Cluster, Air
Conditioning Relay, Turn
Signal/Hazard Switch, Starter
Relay
RTD Ride Control
TRL B/U Backup Lamps Trailer Wiring
PCM BPowertrain Control Module,
Fuel Pump
F/PMP Fuel Pump (Relay)Fuses Usage
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
SIRSupplemental 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
DRL Daytime Running Lamps
IPC/DICInstrument Panel
Cluster/Driver Information
Center
5-116
Page 493 of 552
Fuses Usage
HVAC/ECAS Climate Control Controller
CIG LTR Cigarette Lighter
HI HDLP-RT High Beam Headlamp-Right
HDLP-LOW Headlamp Low Beam Relay
A/C COMP Air Conditioning Compressor
A/C COMPAir Conditioning Compressor
Relay
RR WPR Rear Wiper/Washer
RADIO Audio System
SEO B1Mid Bussed Electrical Center,
HomeLink, Rear Heated
Seats
LO HDLP-LT Headlamp Low Beam-Left
BTSIBrake Transmission Shift
Interlock System
CRANK Starting System
LO HDLP-RT Headlamp Low Beam-RightFuses Usage
FOG LP Fog Lamp Relay
FOG LP Fog Lamps
HORN Horn Fuse
HORN Horn Relay
W/S WASHWindshield and Rear Window
Washer Pump Relay
W/S WASHWindshield and Rear Window
Washer Pump
INFOOnStar/Rear Seat
Entertainment
RADIO AMP Radio Ampli®er
RH HID Not Used
EAP Electric Adjustable Pedals
TREC All-Wheel Drive Module
SBA Supplemental Brake Assist
5-117
Page 499 of 552

Maintenance Schedule......................................6-2
Introduction...................................................6-2
Your Vehicle and the Environment....................6-2
Maintenance Requirements..............................6-2
How This Section is Organized.........................6-3
Part A: Scheduled Maintenance Services...........6-4
Using Your Maintenance Schedule....................6-4
Scheduled Maintenance...................................6-5
Part B: Owner Checks and Services................6-11
At Each Fuel Fill..........................................6-11
At Least Once a Month.................................6-11
At Least Twice a Year...................................6-12
At Least Once a Year...................................6-13Part C: Periodic MaintenanceInspections.........6-16
Steering and Suspension Inspection................6-16
Exhaust System Inspection............................6-16
Fuel System Inspection..................................6-16
Engine Cooling System Inspection...................6-17
Transfer Case and Front Axle (Four-Wheel
Drive) Inspection.......................................6-17
Brake System Inspection................................6-17
Part D: Recommended Fluids and Lubricants. . . .6-18
Part E: Maintenance Record...........................6-20
Section 6 Maintenance Schedule
6-1
Page 503 of 552

Scheduled Maintenance
The services shown in this schedule up to 100,000 miles
(166 000 km) should be repeated after 100,000 miles
(166 000 km) at the same intervals for the life of
this vehicle. The services shown at 150,000 miles
(240 000 km) should be repeated at the same interval
after 150,000 miles (240 000 km) for the life of this
vehicle.
See
Part B: Owner Checks and Services on page 6-11andPart C: Periodic MaintenanceInspections on
page 6-16.
Footnotes
²The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to
the completion of the vehicle's useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.
+A good time to check your brakes is during tire
rotation. See Brake System Inspection on page 6-17.
Engine Oil and Chassis Lubrication
Scheduled Maintenance
Change engine oil and ®lter as indicated by the GM
Oil Life System (or every 12 months, whichever
occurs ®rst). Reset the system.
Your vehicle has a computer system that lets you know
when to change the engine oil and ®lter. This is based on
engine revolutions and engine temperature, and not on
mileage. Based on driving conditions, the mileage at
which an oil change will be indicated can vary
considerably. For the oil life system to work properly, you
must reset the system every time the oil is changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE ENGINE OIL message will
come on. Change your oil as soon as possible within
the next two times you stop for fuel. It is possible that, if
you are driving under the best conditions, the oil life
system may not indicate that an oil change is necessary
for over a year. However, your engine oil and ®lter
must be changed at least once a year and at this time
the system must be reset. Your dealer has GM-trained
service people who will perform this work using
genuine GM parts and reset the system.
It is also important to check your oil regularly and keep
it at the proper level.
6-5