
*1— Gasoline Engine and Fuel Injection Rail #2.
*2— Gasoline Engine and Fuel Injection Rail
#1.
*3— Gasoline Engine; Oxygen Sensors.
*4— Gasoline Engine; Oxygen Sensors.
*5— Ignition 1
*6— Powertrain Control Module, Fuel Pump.
*7— Supplemental Brake Assist.
*8— Sunroof.
Fuses Usage
GLOW PLUG Not Used
CUST FEED Gasoline Accessory Power
HYBRID Not Used
WSW/HTRHeated Windshield Washer
(Special Edition Only)
STUD #1Accessory Power/Trailer
Wiring
MBEC 1Mid Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
Fuses Usage
BLWR Front Climate Control Fan
LBEC 2Left 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/ECASElectronically Controlled Air
Suspension
IGN A Ignition Switch
IGN B Ignition Switch
LBEC 1Left Bussed Electrical Center,
Left Doors, Truck Body
Controller, Flasher Module
TRL PARK Parking Lamps Trailer Wiring
RR PARKPassenger’s Side Rear
Parking and Sidemarker
Lamps
LR PARKDriver’s Side Rear Parking
and Sidemarker Lamps
509

Fuses Usage
PARK LP Parking Lamps Relay
STRTR Starter Relay
INTPARK Roof Marker Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller
Battery Feed
SEO B2 Off-Road Lamps
4WS Not Used
AUX PWRInstrument Panel Outlets,
Rear Cargo Area Power
Outlets, Console
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, Electronic Brake
Controller TC2 Mode Switch
RTDElectronic Brake Controller
Battery FeedFuses Usage
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-LTDriver’s Side High Beam
Headlamp
LH HID Not Used
DRL Daytime Running Lamps
510

Additional Required Services (cont’d)
Service and Miles (Kilometers)25,000
(40 000)50,000
(80 000)75,000
(120 000)100,000
(160 000)125,000
(200 000)150,000
(240 000)
Engine cooling system service (or every
ve years, whichever occurs rst).
An Emission Control Service.
See footnote (i).•
Inspect engine accessory drive belt.
An Emission Control Service.
See footnote (k).•
Maintenance Footnotes
#Lubricate the front suspension, steering linkage,
transmission shift linkage, and parking brake
cable guides. Control arm ball joints require
lubrication but should not be lubricated unless
their temperature is 10°F (-12°C) or higher, or
they could be damaged.
(a)Visually inspect brake lines and hoses for
proper hook-up, binding, leaks, cracks, cha ng,
etc. Inspect disc brake pads for wear and rotors for
surface condition. Inspect other brake parts,
including calipers, parking brake, etc.(b)Visually inspect front and rear suspension and
steering system for damaged, loose, or missing
parts, signs of wear or lack of lubrication. Inspect
power steering lines and hoses for proper
hook-up, binding, leaks, cracks, cha ng, etc.
Visually check constant velocity joints, rubber
boots and axle seals for leaks.
(c)Visually inspect hoses and have them replaced
if they are cracked, swollen, or deteriorated.
Inspect all pipes, ttings, and clamps; replace with
genuine GM parts as needed. To help ensure
proper operation, a pressure test of the cooling
system and pressure cap and cleaning the outside
of the radiator and air conditioning condenser is
recommended at least once a year.
521

At Least Once a Year
Starter Switch Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough
room around the vehicle.
2. Firmly apply both the parking brake and the
regular brake. SeeParking Brake on
page 133.
Do not use the accelerator pedal, and be
ready to turn off the engine immediately if
it starts.3. Try to start the engine in each gear. The
vehicle should start only in PARK (P) or
NEUTRAL (N). If the vehicle starts in any
other position, contact your GM Goodwrench
®
dealer for service.
525

Automatic Transmission Shift Lock
Control System Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough
room around the vehicle. It should be parked
on a level surface.
2. Firmly apply the parking brake. SeeParking
Brake on page 133.
Be ready to apply the regular brake
immediately if the vehicle begins to move.
3. With the engine off, turn the ignition to RUN,
but do not start the engine. Without applying
the regular brake, try to move the shift
lever out of PARK (P) with normal effort. If the
shift lever moves out of PARK (P), contact
your GM Goodwrench
®dealer for service.
Ignition Transmission Lock Check
While parked, and with the parking brake set, try
to turn the ignition to LOCK in each shift lever
position.
The ignition should turn to LOCK only when
the shift lever is in PARK (P).
The ignition key should come out only
in LOCK.
Contact your GM Goodwrench
®dealer if service is
required.
526

Parking Brake and Automatic
Transmission Park (P) Mechanism Check
{CAUTION:
When you are doing this check, your
vehicle could begin to move. You or
others could be injured and property
could be damaged. Make sure there is
room in front of your vehicle in case it
begins to roll. Be ready to apply the
regular brake at once should the vehicle
begin to move.Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular
brake, set the parking brake.
To check the parking brake’s holding ability:
With the engine running and transmission in
NEUTRAL (N), slowly remove foot pressure
from the regular brake pedal. Do this until the
vehicle is held by the parking brake only.
To check the PARK (P) mechanism’s holding
ability: With the engine running, shift to
PARK (P). Then release the parking brake
followed by the regular brake.
Contact your GM Goodwrench
®dealer if service is
required.
Underbody Flushing Service
At least every spring, use plain water to ush any
corrosive materials from the underbody. Take
care to clean thoroughly any areas where mud and
other debris can collect.
527

Appearance Care (cont.)
Tires........................................................ 499
Underbody Maintenance........................... 500
Vehicle Care/Appearance Materials.......... 501
Washing Your Vehicle.............................. 495
Weatherstrips........................................... 495
Windshield, Backglass, and
Wiper Blades........................................ 498
Wood Panels........................................... 495
Ashtray(s).................................................... 197
Assist Steps................................................ 338
Audio System(s).......................................... 241
Audio Steering Wheel Controls................. 296
Care of Your Cassette Tape Player.......... 297
Care of Your CD and DVD Player............ 300
Care of Your CDs and DVDs................... 299
Chime Level Adjustment........................... 300
Fixed Mast Antenna................................. 300
Navigation/Radio System,
see Navigation Manual......................... 271
Radio with Cassette and CD.................... 243
Radio with Six-Disc CD............................ 256
Rear Seat Audio (RSA)............................ 294
Setting the Time...................................... 243Audio System(s) (cont.)
Theft-Deterrent Feature............................ 295
Understanding Radio Reception............... 297
XM™ Satellite Radio Antenna System........ 300
Automatic Headlamp System....................... 189
Automatic Transmission
Fluid........................................................ 412
Operation................................................. 124
B
Battery........................................................ 431
Run-Down Protection............................... 192
Before Leaving on a Long Trip.................... 349
Bench Seat, Split (60/40).............................. 15
Brake
Anti-Lock Brake System (ABS)................. 307
Emergencies............................................ 309
Parking.................................................... 133
System Warning Light.............................. 211
Brakes........................................................ 427
Braking....................................................... 306
Braking in Emergencies............................... 309
Break-In, New Vehicle................................. 119
556

P
Paint, Damage............................................ 499
Park Aid...................................................... 192
Park (P)
Shifting Into............................................. 134
Shifting Out of......................................... 135
Parking
Brake....................................................... 133
Over Things That Burn............................ 136
Passing....................................................... 314
Passlock
®.................................................... 118
Power
Accessory Outlet(s).................................. 196
Door Locks.............................................. 101
Electrical System..................................... 503
Lumbar Controls.......................................... 9
Reclining Seatbacks................................... 12
Retained Accessory (RAP)....................... 121
Seat............................................................ 8
Steering Fluid.......................................... 425
Windows.................................................. 112
Power Winch Platform................................. 361
Programmable Automatic Door Locks.......... 102
Q
Questions and Answers About
Safety Belts............................................... 28
R
Radios........................................................ 241
Care of Your Cassette Tape Player.......... 297
Care of Your CD and DVD Player............ 300
Care of Your CDs and DVDs................... 299
Navigation/Radio System,
see Navigation Manual......................... 271
Radio with Cassette and CD.................... 243
Radio with Six-Disc CD............................ 256
Rear Seat Audio...................................... 294
Setting the Time...................................... 243
Theft-Deterrent......................................... 295
Understanding Reception......................... 297
Reading Lamps........................................... 192
Rear Axle.................................................... 437
Locking.................................................... 311
Rear Door Security Locks........................... 102
Rear Heated Seats....................................... 15
565