Page 264 of 432

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.
If you have an automatic transmission, you should use
THIRD (3) when towing a trailer. Operating your
vehicle in THIRD (3) when towing a trailer will minimize
heat buildup and extend the life of your transmission.
Or, if you have a manual transmission, it's better not to
use FIFTH (5). Just drive in FOURTH (4) (or, as you
need to, a lower gear).
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) (or
the manual transmission out of gear and the parking
brake applied) for a few minutes before turning the
engine off. If you do get the overheat warning,
see
Engine Overheating on page 5-30.
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, or into gear for a manual
transmission. When parking uphill, turn your wheels
away from the curb. When parking downhill, turn
your wheels into the curb.
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.
4-62
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4. Reapply the regular brakes. Then apply your
parking brake, and then shift into PARK (P), or
REVERSE (R) for a manual transmission.
5. If you have a four-wheel-drive vehicle with an
automatic transfer case, be sure the transfer case is
in a drive gear±not in NEUTRAL.
6. 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. SeePart A: Scheduled Maintenance
Services on page 6-4for more on this. Things that are
especially important in trailer operation are automatic
transmission ¯uid (don't over®ll), engine oil, axle
lubricant, belt, cooling system and brake system. Each
of these is covered in this manual, and the Index
will help you ®nd 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.
4-63
Page 267 of 432

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.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under
the Hood....................................................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-15
Engine Air Cleaner/Filter................................5-19
Automatic Transmission Fluid.........................5-22
Manual Transmission Fluid.............................5-25
Hydraulic Clutch...........................................5-26
Engine Coolant.............................................5-27Radiator Pressure Cap..................................5-29
Engine Overheating.......................................5-30
Cooling System............................................5-32
Engine Fan Noise.........................................5-39
Power Steering Fluid.....................................5-39
Windshield Washer Fluid................................5-40
Brakes........................................................5-41
Battery........................................................5-45
Jump Starting...............................................5-46
Rear Axle.......................................................5-51
Four-Wheel Drive............................................5-52
Front Axle......................................................5-53
Bulb Replacement..........................................5-54
Halogen Bulbs..............................................5-54
Headlamps..................................................5-54
One-Piece Front Turn Signal Lamps................5-56
Two-Piece Front Turn Signal Lamps................5-57
Center High-Mounted Stoplamp (CHMSL).........5-58
Taillamps.....................................................5-59
Replacement Bulbs.......................................5-59
Windshield Wiper Blade Replacement..............5-60
Section 5 Service and Appearance Care
5-1
Page 279 of 432
A. Battery
B. Coolant Recovery Tank
C. Automatic Transmission Dipstick (If Equipped)
D. Engine Oil Fill Cap and Dipstick
E. Power Steering ReservoirF. Brake Master Cylinder
G. Engine Air Cleaner/Filter
H. Engine Compartment Fuse Block
I. Windshield Washer Fluid Reservoir
5-13
Page 281 of 432
A. Battery
B. Coolant Recovery Tank
C. Engine Oil Dipstick
D. Engine Oil Fill
E. Automatic Transmission Dipstick (If Equipped)
F. Power Steering Reservoir
G. Brake Master Cylinder Reservoir
H. Engine Air Cleaner/Filter
I. Engine Compartment Fuse Block
J. Windshield Washer Fluid ReservoirEngine Oil
Checking Engine Oil
It's 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 on the
ªVORTECŸ º 4300 V6
engine is a yellow ring.
See
Engine Compartment Overview on page 5-12for
more information on location.
5-15
Page 288 of 432

Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission ¯uid
level is when the engine oil is changed.
Change both the ¯uid and ®lter every 15,000 miles
(25 000 km) if the vehicle is mainly driven under one or
more of these conditions:
·In heavy city traffic where the outside temperature
regularly reaches 90ÉF (32ÉC) or higher.
·In hilly or mountainous terrain.
·When doing frequent trailer towing.
·Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change the ¯uid and ®lter every
50,000 miles (83 000 km).
See
Part A: Scheduled Maintenance Services on
page 6-4.
How to Check
Because this operation can be a little difficult, you may
choose to have this done at the dealership service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice:Too much or too little ¯uid can damage
your transmission. Too much can mean that some
of the ¯uid could come out and fall on hot engine
part or exhaust system parts, starting a ®re.
Too little ¯uid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission ¯uid.
Wait at least 30 minutes before checking the
transmission ¯uid level if you have been driving:
·When outside temperatures are above 90ÉF (32ÉC).
·At high speed for quite a while.
·In heavy traffic±especially in hot weather.
·While pulling a trailer.
5-22
Page 291 of 432

Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
changed. However, the ¯uid in your manual transmission
doesn't require changing.
How to Check
Because this operation can be a little difficult, you may
choose to have this done at your GM dealership
service department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading.
Notice:Too much or too little ¯uid can damage
your transmission. Too much can mean that some
of the ¯uid could come out and fall on hot engine
part or exhaust system parts, starting a ®re.
Too little ¯uid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission ¯uid.
Check the ¯uid level only when your engine is off, the
vehicle is parked on a level place and the transmission
is cool enough for you to rest your ®ngers on the
transmission case.Then, follow these steps:
1. Remove the ®ller plug.
2. Check that the lubricant level is up to the bottom of
the ®ller plug hole.
3. If the ¯uid level is good, install the plug and be sure
it is fully seated. If the ¯uid level is low, add more
¯uid as described in the next steps.
5-25
Page 363 of 432
Fuse Usage
LT TRN Left Turn Signal Rear
RT TRN Right Turn Signal Rear
RR PRK Right Rear Parking Lamps
TRL PRK Trailer Park Lamps
LTHDLP Left Headlamp
RTHDLP Right Headlamp
FRPRK Front Parking Lamps
INT BAT Instrument Panel Fuse Block Feed
ENG IEngine Sensors/Solenoids, MAF,
CAM, PURGE, VENT
ECM BEngine Control Module, Fuel Pump
Module, Oil Pressure
ABS Anti-Lock Brake System
ECM I Engine Control Module Injectors
F/PUMP Fuel Pump
DRL Daytime Running LampsFuse Usage
A/C Air Conditioning
HORN Horn
W/W PMP Not Used
HORN Horn
BTSIAutomatic Transmission Shift Lock
Control System
B/U LP Back Up Lamps
IGN B Column Feed,Ignition 2, 3, 4
STARTER Starter
RAP Retained Accessory Power
LD LEV Not Used
OXYSEN Oxygen Sensor
IGN E Engine
MIR/LKS Mirrors, Door Locks
FOG LP Fog Lamps
IGN A Starting and Charging Ignition 1
5-97