
The seven-wire harness contains the following trailer
circuits:
·Yellow: Left Stop/Turn Signal
·Dark Green: Right Stop/Turn Signal
·Brown: Taillamps
·White: Ground
·Light Green: Back-up Lamps
·Red: Battery Feed
·Dark Blue: Trailer Brake
A jumper harness for an electric trailer brake controller
and a trailer battery feed fuse may be included with
this trailering package. See ªInstrument Panel Jumper
Wiring Harnessº later in this section.
If you need to tow a light-duty trailer with a standard
four-way, round pin connector, an adapter may be
included. See ªFour-Wire Harness Adapterº later in this
section.
Instrument Panel Jumper Wiring Harness
This harness may be included with your vehicle as part
of the heavy-duty trailer wiring package.
This harness is for an electric brake controller and
includes a trailer battery feed fuse. It should be installed
by your dealer or a quali®ed service center.
4-65

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside of Your
Vehicle......................................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Speci®cations....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-5
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-6
Filling a Portable Fuel Container.......................5-8
Checking Things Under the Hood.....................5-8
Hood Release................................................5-9
Engine Compartment Overview.......................5-10
Engine Oil...................................................5-11
Engine Air Cleaner/Filter................................5-16
Automatic Transmission Fluid.........................5-19
Engine Coolant.............................................5-22
Coolant Surge Tank Pressure Cap..................5-25
Engine Overheating.......................................5-26
Cooling System............................................5-28
Engine Fan Noise.........................................5-34Power Steering Fluid.....................................5-35
Windshield Washer Fluid................................5-36
Brakes........................................................5-38
Battery........................................................5-41
Jump Starting...............................................5-42
All-Wheel Drive..............................................5-48
Rear Axle.......................................................5-49
Front Axle......................................................5-50
Headlamp Aiming...........................................5-51
Headlamp Horizontal Aiming...........................5-52
Headlamp Vertical Aiming..............................5-53
Bulb Replacement..........................................5-55
High Intensity Discharge (HID) Lighting............5-55
Halogen Bulbs..............................................5-55
Headlamps..................................................5-56
Front Turn Signal, Sidemarker and Daytime
Running Lamps.........................................5-60
Center High-Mounted Stoplamp (CHMSL).........5-61
Taillamps.....................................................5-61
Replacement Bulbs.......................................5-62
Windshield Wiper Blade Replacement..............5-62
Section 5 Service and Appearance Care
5-1

Notice:
·Using the wrong ¯uid can badly damage brake
system parts. For example, just a few drops of
mineral-based oil, such as engine oil, in your
brake system can damage brake system
parts so badly that they will have to be replaced.
Do not let someone put in the wrong kind of
¯uid.
·If you spill brake ¯uid on your vehicle's painted
surfaces, the paint ®nish can be damaged. Be
careful not to spill brake ¯uid on your vehicle. If
you do, wash it off immediately. See
Appearance
Care on page 5-102.
Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that make
a high-pitched warning sound when the brake pads
are worn and new pads are needed. The sound
may come and go or be heard all the time your vehicle
is moving (except when you are pushing on the
brake pedal ®rmly).
{CAUTION:
The brake wear warning sound means that
soon your brakes will not work well. That
could lead to an accident. When you hear the
brake wear warning sound, have your vehicle
serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates may cause a brake
squeal when the brakes are ®rst applied or lightly
applied. This does not mean something is wrong with
your brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence to GM torque speci®cations.
Brake linings should always be replaced as complete
axle sets.
5-40

Notice:Ignoring these steps could result in costly
damage to your vehicle that would not be covered
by your warranty.
Trying to start your vehicle by pushing or pulling it
will not work, and it could damage your vehicle.
1. Check the other vehicle. It must have a 12-volt
battery with a negative ground system.
Notice:If the other vehicle's system is not a 12-volt
system with a negative ground, both vehicles can
be damaged. Only use vehicles with 12-volt systems
with negative grounds to jump start your vehicle.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren't touching
each other. If they are, it could cause a ground
connection you don't want. You wouldn't be able to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake ®rmly on both vehicles involved in
the jump start procedure. Put an automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL before setting the parking brake.
Notice:If you leave your radio or other accessories
on during the jump starting procedure, they could
be damaged. The repairs would not be covered
by your warranty. Always turn off your radio and
other accessories when jump starting your vehicle.3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or accessory power outlets. Turn off the
radio and all lamps that aren't needed. This
will avoid sparks and help save both batteries. And
it could save your radio!
4. Open the hoods and locate the positive (+) and
negative (-) terminal locations of the other vehicle.
Your vehicle has a remote positive (+) jump
starting terminal and a remote negative (-) jump
starting terminal. You should always use these
remote terminals instead of the terminals on the
battery.
The remote positive (+)
terminal is located near the
engine accessory drive
bracket. On some vehicles,
the terminal may be
covered under under a red
plastic cover. To access
the remote positive (+)
terminal, open the
red plastic cover.
5-43

(A) Light Truck (LT-Metric) Tire:The United States
version of a metric tire sizing system. The letter ªLTº as
the ®rst two characters in the tire size means a light
truck tire engineered to standards set by the U. S. Tire
and Rim Association.
(B) Tire Width:The three-digit number indicates the
tire section width in millimeters from sidewall to sidewall.
(C) Aspect Ratio:A two-digit number that indicates
the tire height-to-width measurements. For example, if
the tire size aspect ratio is ª75,º as shown in item ªCº of
the illustration, it would mean that the tire's sidewall is
75% as high as it is wide.(D) Construction Code:A letter code is used to
indicate the type of ply construction in the tire. The
letter ªRº means radial ply construction; the letter ªDº
means diagonal or bias ply construction; and the
letter ªBº means belted-bias ply construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:The service description
indicates the load range and speed rating of a tire. The
load index can range from 1 to 279. Speed ratings
range from ªAº to ªZº. The light truck tire size example
above shows dual or single tire con®gurations.Tire Terminology and De®nitions
Air Pressure:The amount of air inside the tire pressing
outward on each square inch of the tire. Air pressure
is expressed in pounds per square inch (psi) or
kilopascal (kPa).
Accessory Weight:This means the combined weight
of optional accessories. Some examples of optional
accessories are, automatic transmission, power steering,
power brakes, power windows, power seats, and air
conditioning.
Aspect Ratio:The relationship of a tire's height to
its width.
Belt:A rubber coated layer of cords that is located
between the plies and the tread. Cords may be made
from steel or other reinforcing materials. Light Truck (LT-Metric) Tire
5-68

TPM Sensor Identi®cation Codes
Each TPM sensor has a unique identi®cation code. Any
time you rotate your vehicle's tires or replace one or
more of the TPM sensors, the identi®cation codes
will need to be matched to the new tire/wheel position.
Each tire/wheel position is matched to a sensor, by
increasing or decreasing the tire's air pressure.
The sensors are matched to the tire/wheel positions in
the following order: left front (LF); right front (RF);
right rear (RR) and left rear (LR).
You will have one minute to match the ®rst tire/wheel
position, and ®ve minutes overall to match all four
tire/wheel positions. If it takes longer than one minute,
to match the ®rst tire and wheel, or more than ®ve
minutes to match all four tire and wheel positions the
matching process stops and you will need to start over.
The TPM sensor matching process is outlined below:
1. Set the Parking brake.
2. Turn the ignition switch to RUN with the engine off.3. Turn the exterior lamp switch from ªOffº to ªOnº
four times within 3 seconds. A double horn chirp
will sound and the TPM low tire warning light
will begin to ¯ash. The double horn chirp and
¯ashing TPM warning light indicate that the TPM
matching process has started. The TPM warning
light should continue ¯ashing throughout the
matching procedure. The SERVICE TIRE
MONITOR message will be displayed on the Driver
Information Center (DIC).
4. Start with the left (driver's side) front tire.
5. Remove the valve cap from the valve cap stem.
Activate the TPM sensor by increasing or
decreasing the tire's air pressure for 10 seconds,
then stop and listen for a single horn chirp.
The single horn chirp should sound within
15 seconds, con®rming that the sensor identi®cation
code has been matched to this tire and wheel
position. If you do not hear the con®rming single
horn chirp, you will need to start over with step
number one. To let air-pressure out of a tire you can
use the pointy end of the valve cap, a pencil-style
air pressure gage or a key.
5-73

Fuses Usage
LH HIDLeft Hand High Intensity
Discharge Lamps
DRL Daytime Running Lamps
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
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 SystemFuses Usage
CRANK Starting System
LO HDLP - RT Headlamp Low Beam - Right
FOG LP Fog Lamp Relay
FOG LP Fog Lamps
HORN Horn Relay
W/S WASHWindshield and Rear Window
Washer Pump Relay
W/S WASHWindshield and Rear Window
Washer Pump
INFO OnStar/Rear Seat Entertainment
RADIO AMP Radio Ampli®er
RH HIDRight Hand High Intensity
Discharge Lamp
HORN Horn Fuse
EAP Electric Adjustable Pedals
TREC All-Wheel Drive Module
SBA Supplemental Brake Assist
5-119

Maintenance 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.
#Lubricate the front suspension, ball joints, steering
linkage, transmission shift linkage and parking
brake cable guides. Ball joints should not be lubricated
unless their temperature is 10ÉF (-12ÉC) 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.
(d)Visually inspect wiper blades for wear or cracking.
Replace blade inserts that appear worn or damaged
or that streak or miss areas of the windshield.
(e)Make sure the safety belt reminder light and all your
belts, buckles, latch plates, retractors and anchorages
are working properly. Look for any other loose or
damaged safety belt system parts. If you see anything
that might keep a safety belt system from doing its
job, have it repaired. Have any torn or frayed safety belts
replaced. Also look for any opened or broken air bag
coverings, and have them repaired or replaced. (The air
bag system does not need regular maintenance.)
(f)Lubricate all key lock cylinders, hood latch assembly,
secondary latch, pivots, spring anchor, release pawl,
rear compartment hinges, outer tailgate handle
pivot points, latch bolt, fuel door hinge and folding seat
hardware. More frequent lubrication may be required
when exposed to a corrosive environment. Applying
silicone grease on weatherstrips with a clean cloth will
make them last longer, seal better and not stick or
squeak.
6-8