Page 274 of 427
4-57 Trailer Wiring Harness
Heavy-Duty Trailer Wiring Package
Your vehicle is equipped with the seven-wire trailer
towing harness. This harness with a seven
-pin universal
heavy
-duty trailer connector is attached to a bracket on
the platform hitch.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 are 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 connector
is included with the vehicle. See ªFour
-Wire Trailer
Harness Adapterº later in this section.
Page 275 of 427
4-58
Instrument Panel Jumper Wiring Harness
This harness is included with the trailer wiring package.
The harness is for an electric trailer brake controller and
includes a trailer battery feed fuse. This harness and
fuse should be installed by your dealer or a qualified
service center.Four
-Wire Trailer Harness Adapter
If you need to tow a
light
-duty trailer with a
standard four
-way round
pin connector, an adapter
is included.
Connect the adapter with the tab (arrow) pointing towards
the top. The cap on the wiring harness will lock onto the
tab (arrow) and help hold the adapter in place. Plug the
four
-way round pin connector into the adapter.
Page 279 of 427

5-4
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 firmly 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 on, it could be badly
damaged. The repairs wouldn't be covered by
your warranty.
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 under a
red plastic cover near the engine accessory drive
bracket. To access the remote positive (+) terminal,
open the red plastic cover.
The remote negative (
-) terminal is located on the
engine accessory drive bracket and is marked ªGND.º
See ªEngine Compartment Overviewº in the Index
for more information on location.
Page 294 of 427

5-19
Engine Fan Noise
Your vehicle has a clutched engine cooling fan.
When the clutch is engaged, the fan spins faster to
provide more air to cool the engine. In most everyday
driving conditions, the fan is spinning slower and
the clutch is not fully engaged. This improves fuel
economy and reduces fan noise. Under heavy vehicle
loading, trailer towing and/or high outside temperatures,
the fan speed increases as the clutch more fully engages.
So you may hear an increase in fan noise. This is
normal and should not be mistaken as the transmission
slipping or making extra shifts. It is merely the cooling
system functioning properly. The fan will slow down
when additional cooling is not required and the
clutch disengages.
You may also hear this fan noise when you start
the engine. It will go away as the fan clutch
partially disengages.
If a Tire Goes Flat
It's unusual for a tire to ªblow outº while you're driving,
especially if you maintain your tires properly. If air goes
out of a tire, it's much more likely to leak out slowly.
But if you should ever have a ªblowout,º here are a
few tips about what to expect and what to do:
If a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side. Take your foot off
the accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake
to a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like
a skid and may require the same correction you'd use
in a skid. In any rear blowout, remove your foot from
the accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go. It may be
very bumpy and noisy, but you can still steer. Gently
brake to a stop
-- well off the road if possible.
If a tire goes flat, the next part shows how to use your
jacking equipment to change a flat tire safely.
Page 295 of 427
5-20
Changing a Flat Tire
If a tire goes flat, avoid further tire and wheel damage
by driving slowly to a level place. Turn on your hazard
warning flashers.
CAUTION:
Changing a tire can cause an injury. The vehicle
can slip off the jack and roll over you or other
people. You and they could be badly injured.
Find a level place to change your tire. To help
prevent the vehicle from moving:
1. Set the parking brake firmly.
2. Put the shift lever in PARK (P).
3. Turn off the engine.
4. Put the wheel blocks at the front and
rear of the tire farthest away from the
one being changed. That would be the
tire on the other side of the vehicle,
at the opposite end.The following steps will tell you how to use the jack and
change a tire.
Page 306 of 427
5-31
CAUTION:
Incorrect wheel nuts or improperly tightened
wheel nuts can cause the wheel to become 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. See ªCapacities and Specificationsº in
the Index.
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 specification.
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 flush 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.
Page 313 of 427

6-
6-1
Section 6 Service and Appearance Care
Here you will find information about the care of your vehicle. This section begins with service and fuel information,
and then it shows how to check important fluid and lubricant levels. There is also technical information about your
vehicle, and a part devoted to its appearance care.
6
-2 Service
6
-3 Fuel
6
-5 Fuels in Foreign Countries
6
-6 Filling Your Tank
6
-8 Filling a Portable Fuel Container
6
-8 Checking Things Under the Hood
6
-11 Engine Oil
6
-17 Engine Air Cleaner/Filter
6
-19 Passenger Compartment Air Filter
6
-19 Automatic Transmission Fluid
6
-23 Rear Axle
6
-23 All-Wheel Drive
6
-26 Engine Coolant
6
-29 Coolant Surge Tank Pressure Cap
6
-30 Power Steering Fluid6
-31 Windshield Washer Fluid
6
-32 Brakes
6
-36 Battery
6
-37 Bulb Replacement
6
-49 Windshield Wiper Blade Replacement
6
-50 Tires
6
-58 Appearance Care
6
-59 Cleaning the Inside of Your Vehicle
6
-61 Cleaning the Outside of Your Vehicle
6
-65 GM Vehicle Care/Appearance Materials
6
-66 Vehicle Identification Number (VIN)
6
-67 Electrical System
6
-75 Replacement Bulbs
6
-76 Capacities and Specifications
6
-77 Normal Maintenance Replacement Parts
Page 320 of 427

6-8
Filling a Portable Fuel Container
CAUTION:
Never fill a portable fuel container while it is in
your vehicle. Static electricity discharge from the
container can ignite the gasoline vapor. You can
be badly burned and your vehicle damaged if this
occurs. To help avoid injury to you and others:
Dispense gasoline only into approved
containers.
Do not fill a container while it is inside a
vehicle, in a vehicle's trunk, pickup bed or
on any surface other than the ground.
Bring the fill nozzle in contact with the
inside of the fill opening before operating
the nozzle. Contact should be maintained
until the filling is complete.
Don't smoke while pumping gasoline.
Checking Things Under the Hood
CAUTION:
Things that burn can get on hot engine parts and
start a fire. These include liquids like fuel, oil,
coolant, brake fluid, windshield washer and other
fluids, and plastic or rubber. You or others could
be burned. Be careful not to drop or spill things
that will burn onto a hot engine.