Page 233 of 412

4-41 Driving On Grades
Reduce speed and shift to a lower gear before you start
down a long or steep downgrade. If you don't shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude on
steep uphill grades, your vehicle may show signs similar to
engine overheating. To avoid this, let the engine run while
parked (preferably on level ground) with the automatic
transmission in PARK (P) for a few minutes before turning
the engine off. If you do get the overheat warning, see
ªEngine Overheatingº in the Index.
Parking on Hills
CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People can
be injured, and both your vehicle and the trailer
can be damaged.
But if you ever have to park your rig on a hill, here's
how to do it:
1. Apply your regular brakes, but don't shift into
PARK (P) yet. Then turn your wheels into the curb if
facing downhill or into traffic if facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your parking
brake and then shift to PARK (P).
5. Release the regular brakes.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
Start your engine;
Shift into a gear; and
Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Page 234 of 412

4-42 Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don't overfill),
engine oil, axle lubricant, belt, cooling system and brake
system. Each of these is covered in this manual, and the
Index will help you find them quickly. If you're trailering,
it's a good idea to review these sections before you
start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
The optional heavy-duty trailer wiring package is a
seven
-wire harness assembly. The four-wire portion of
the harness assembly is stored under the vehicle, along
the driver's side rear corner of the frame rail. The
three
-wire portion of the harness assembly is stored in a
frame pocket under the rear of the vehicle, on the
driver's side. The heavy
-duty trailer wiring harness has
a 30
-amp feed wire. Both harnesses come without
connectors and should be wired by a qualified electrical
technician. The technician can use the following color
code chart when connecting the wiring harness to
your trailer.Four
-Wire Harness
Light Green: Back
-up lamps
Brown: Parking lamps
Yellow: Left stoplamp and turn signal
Dark Green: Right stoplamp and turn signal
Three
-Wire Harness
Dark Blue: Use for electric trailer brakes
(seven
-wire harness only)
Orange: Trailer accessory (seven
-wire harness only)
White (heavy gage): Ground wire
Securely attach the harness to the trailer, then tape or
strap it to your vehicle's frame rail. Be sure you leave it
loose enough so the wiring doesn't bend or break, but
not so loose that it drags on the ground. Store the
harness in its original place. Wrap the harness together
and tie it neatly so it won't be damaged.
Page 246 of 412
5-12
Cooling System (Gasoline Engine)
When you decide it's safe to lift the hood, here's what
you'll see:
A. Radiator Pressure Cap
B. Coolant Recovery Tank
C. Engine Cooling Fan(s)
If the coolant inside the coolant recovery tank is boiling,
don't do anything else until it cools down.
When the engine is cold, the coolant level should be at
or above the FULL COLD mark.
If it isn't, you may have a leak in the radiator hoses,
heater hoses, radiator, water pump or somewhere else in
the cooling system.
Page 248 of 412

5-14 How to Add Coolant to the Coolant
Recovery Tank
If you haven't found a problem yet, but the coolant level
isn't at the FULL COLD mark, add a 50/50 mixture of
clean, drinkable water and DEX
-COOL engine
coolant at the coolant recovery tank. See ªEngine
Coolantº in the Index for more information.
See ªEngine Compartment Overviewº in the Index
for more information on location.
CAUTION:
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid like alcohol, can boil before the proper
coolant mixture will. Your vehicle's coolant
warning system is set for the proper coolant
mixture. With plain water or the wrong mixture,
your engine could get too hot but you wouldn't
get the overheat warning. Your engine could
catch fire and you or others could be burned.
Use a 50/50 mixture of clean, drinkable water
and DEX
-COOL coolant.
NOTICE:
In cold weather, water can freeze and crack the
engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
Page 264 of 412
5-30
CAUTION:
Rust or dirt on the wheel, or on the parts to
which it is fastened, can make the wheel nuts
become loose after a time. The wheel could come
off and cause an accident. When you change a
wheel, remove any rust or dirt from the places
where the wheel attaches to the vehicle. In an
emergency, you can use a cloth or a paper towel
to do this; but be sure to use a scraper or wire
brush later, if you need to, to get all the rust or
dirt off.
CAUTION:
Never use oil or grease on studs or nuts. If you
do, the nuts might come loose. Your wheel could
fall off, causing a serious accident.
8. Put the wheel nuts back
on with the rounded end
of the nuts toward the
wheel. Tighten each
wheel nut by hand until
the wheel is held against
the hub.
9. Lower the vehicle by turning the jack handle
counterclockwise. Lower the jack completely.
Page 270 of 412

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 (Gasoline Engine)
6
-5 Fuels in Foreign Countries (Gasoline Engines)
6
-5 Filling Your Tank (Gasoline Engine)
6
-7 Filling a Portable Fuel Container
6
-8 Checking Things Under the Hood
6
-11 Noise Control System
6
-12 Engine Oil (Gasoline Engine)
6
-16 Engine Air Cleaner/Filter (Gasoline Engines)
6
-18 Automatic Transmission Fluid
6
-22 Rear Axle
6
-22 Engine Coolant
6
-26 Radiator Pressure Cap
6
-26 Power Steering Fluid
6
-27 Windshield Washer Fluid
6
-28 Brakes
6
-32 Battery6
-33 Bulb Replacement
6
-40 Windshield Wiper Blade Replacement
6
-41 Tires
6
-50 Appearance Care
6
-51 Cleaning the Inside of Your Vehicle
6
-54 Cleaning the Outside of Your Vehicle
6
-56 Cleaning Aluminum Wheels (If Equipped)
6
-56 Cleaning Tires
6
-56 Sheet Metal Damage
6
-57 Finish Damage
6
-58 GM Vehicle Care/Appearance Materials
6
-59 Vehicle Identification Number (VIN)
6
-60 Electrical System
6
-66 Replacement Bulbs
6
-67 Capacities and Specifications
6
-70 Normal Maintenance Replacement Parts
Page 274 of 412

6-5
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent deposits from forming in your engine and fuel
system, allowing your emission control system to
function properly. Therefore, you should not have to add
anything to the fuel. In addition, gasolines containing
oxygenates, such as ethers and ethanol, and
reformulated gasolines may be available in your area to
contribute to clean air. General Motors recommends that
you use these gasolines, particularly if they comply with
the specifications described earlier.
NOTICE:
Your vehicle was not designed for fuel that
contains methanol. Don't use it. It can corrode
metal parts in your fuel system and also damage
plastic and rubber parts. That damage wouldn't
be covered under your warranty.
Fuels in Foreign Countries
(Gasoline Engines)
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard to
find. Never use leaded gasoline or any other fuel not
recommended in the previous text on fuel. Costly repairs
caused by use of improper fuel wouldn't be covered by
your warranty.
To check on fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you'll be driving.
Filling Your Tank (Gasoline Engine)
CAUTION:
Gasoline vapor is highly flammable. It burns
violently, and that can cause very bad injuries.
Don't smoke if you're near gasoline or refueling
your vehicle. Keep sparks, flames and smoking
materials away from gasoline.
Page 277 of 412
6-8
Checking Things Under the Hood
CAUTION:
If your vehicle has air conditioning, the auxiliary
engine fan under the hood can start up and
injure you even when the engine is not running.
Keep hands, clothing and tools away from any
underhood electric fan.
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.
Hood Release
To open the hood, first pull
this handle inside the
vehicle. It is located in front
of the driver's side door
frame near the floor.