Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you’re turning with a trailer, make wider turns
than normal. Do this so your trailer won’t strike soft
shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance.
Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle has to have extra
wiring and a heavy-duty turn signal flasher (included
in the optional trailering package).
The arrows on your instrument panel will flash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also flash, telling other drivers
you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will flash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gearbeforeyou 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.
You can tow in DRIVE (D). You may want to shift the
transmission to THIRD (3) or a lower gear under heavy
loads and/or hilly conditions.
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, seeEngine Overheating
on page 5-25.
4-50
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.
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.
4-51
Trailer Wiring Harness
The optional heavy-duty trailer wiring package includes
a seven-wire harness assembly at the rear of the
vehicle and a four-wire harness assembly under the left
hand side of the instrument panel. The seven-wire
harness assembly is taped together and located in a
frame pocket at the driver side rear left corner of
the frame. The seven-wire harness includes 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
and trailer brake controller.Seven-Wire Harness•Light Green: Back-up lamps
•Brown: Parking lamps
•Yellow: Left stoplamp and turn signal
•Dark Green: Right stoplamp and turn signal
•Dark Blue: Use for electric trailer brakes
•Orange: Trailer accessory
•White (heavy gage): Ground wire
Four-Wire Harness (Trailer Brake Controller)
•Black: Ground
•Red/White Stripe: Fused Battery
•Dark Blue: Trailer Brake Feed
•Light Blue: Fused Stoplamp/CHMSL
4-52
Service............................................................5-3
Accessories and Modifications..........................5-3
California Proposition 65 Warning.....................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside
of Your Vehicle...........................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specifications....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil (Gasoline Engine)..........................5-13
Engine Oil Life System (Gasoline Engine)........5-16
Engine Air Cleaner/Filter................................5-18
Automatic Transmission Fluid.........................5-19
Engine Coolant.............................................5-22
Radiator Pressure Cap..................................5-25
Engine Overheating.......................................5-25Cooling System............................................5-26
Engine Fan Noise.........................................5-32
Power Steering Fluid.....................................5-32
Windshield Washer Fluid................................5-33
Brakes........................................................5-34
Battery........................................................5-38
Jump Starting...............................................5-39
All-Wheel Drive..............................................5-43
Rear Axle.......................................................5-44
Front Axle......................................................5-44
Noise Control System.....................................5-45
Tampering with Noise Control System
Prohibited.................................................5-45
Bulb Replacement..........................................5-46
Halogen Bulbs..............................................5-47
Headlamps..................................................5-47
Front Turn Signal, Sidemarker and
Parking Lamps..........................................5-49
Center High-Mounted Stoplamp (CHMSL).........5-50
Taillamps.....................................................5-50
Replacement Bulbs.......................................5-51
Windshield Wiper Blade Replacement..............5-52
Section 5 Service and Appearance Care
5-1
Service
Your dealer knows your vehicle best and wants you to
be happy with it. We hope you will go to your dealer
for all your service needs. You will get genuine GM parts
and GM-trained and supported service people.
We hope you will want to keep your GM vehicle all GM.
Genuine GM parts have one of these marks:
Accessories and Modi cations
When you add non-GM accessories to your vehicle they
can affect your vehicle’s performance and safety,
including such things as, airbags, braking, stability, ride
and handling, emissions systems, aerodynamics,
durability, and electronic systems like anti-lock brakes,
traction control and stability control. Some of these
accessories may even cause malfunction or damage not
covered by warranty.
GM Accessories are designed to complement and
function with other systems on your vehicle. Your
GM dealer can accessorize your vehicle using genuine
GM Accessories. When you go to your GM dealer
and ask for GM Accessories, you will know that
GM-trained and supported service technicians will
perform the work using genuine GM Accessories.
California Proposition 65 Warning
Most motor vehicles, including this one, contain and/or
emit chemicals known to the State of California to
cause cancer and birth defects or other reproductive
harm. Engine exhaust, many parts and systems
(including some inside the vehicle), many fluids,
and some component wear by-products contain
and/or emit these chemicals.
5-3
A. Battery. SeeBattery on page 5-38.
B. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-25.
C. Coolant Recovery Tank. SeeCooling System on
page 5-26.
D. Automatic Transmission Fluid Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 5-19.
E. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil (Gasoline Engine) on page 5-13.
F. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil (Gasoline Engine) on page 5-13.
G. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-18.
H. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-32.
I. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-34.
J. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-33.Engine Oil (Gasoline Engine)
If your vehicle has a diesel engine, see “Engine Oil” in
the DURAMAX®Diesel Engine Supplement.
Checking Engine Oil
It is a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop.
SeeEngine Compartment Overview on page 5-12
for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes
to drain back into the oil pan. If you do not do this,
the oil dipstick might not show the actual level.
2. Pull out the dipstick and clean it with a paper towel
or cloth, then push it back in all the way. Remove it
again, keeping the tip down, and check the level.
5-13
Adding Washer Fluid
Open the cap with the
washer symbol on it. Add
washer fluid until the
tank is full. SeeEngine
Compartment Overview on
page 5-12for reservoir
location.
Notice:
When using concentrated washer uid, follow the
manufacturer’s instructions for adding water.
Do not mix water with ready-to-use washer uid.
Water can cause the solution to freeze and
damage your washer uid tank and other parts of
the washer system. Also, water does not clean as
well as washer uid.
Fill your washer uid tank only three-quarters full
when it is very cold. This allows for expansion if
freezing occurs, which could damage the tank if
it is completely full.
Do not use engine coolant (antifreeze) in your
windshield washer. It can damage your washer
system and paint.
Brakes
Brake Fluid
Your brake master cylinder
reservoir is filled with
DOT-3 brake fluid.
SeeEngine Compartment
Overview on page 5-12
for the location of the
reservoir.
There are only two reasons why the brake fluid level in
the reservoir might go down. The first is that the brake
fluid goes down to an acceptable level during normal
brake lining wear. When new linings are put in, the fluid
level goes back up. The other reason is that fluid is
leaking out of the brake system. If it is, you should have
your brake system fixed, since a leak means that
5 sooner or later your brakes will not work well, or
will not work at all.
5-34
What to Add
When you do need brake fluid, use only DOT-3 brake
fluid. Use new brake fluid from a sealed container
only. SeeRecommended Fluids and Lubricants
(Gasoline Engine) on page 6-13.
Always clean the brake fluid reservoir cap and the area
around the cap before removing it. This will help
keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind of uid in your brake
system, your brakes may not work well, or they
may not even work at all. This could cause a
crash. Always use the proper brake uid.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. SeeWashing
Your Vehicle on page 5-88.
5-36