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 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 287 of 412

6-18
CAUTION:
Operating the engine with the air cleaner/filter
off can cause you or others to be burned. The air
cleaner not only cleans the air, it stops flame if
the engine backfires. If it isn't there, and the
engine backfires, you could be burned. Don't
drive with it off, and be careful working on the
engine with the air cleaner/filter off.
NOTICE:
If the air cleaner/filter is off, a backfire can
cause a damaging engine fire. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/filter in place when
you're driving.
Automatic Transmission Fluid
If your vehicle has a diesel engine, see ªAutomatic
Transmission Fluidº in the Diesel Supplement.
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every 50,000 miles
(83 000 km) if the vehicle's GVWR is over 8,600 or
if the vehicle is mainly driven under one or more of
these conditions:
In heavy city traffic where the outside temperature
regularly reaches 90F (32C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery service.
If your vehicle's GVWR is not over 8,600 and you do not
use your vehicle under any of these conditions, change the
fluid and filter every 100,000 miles (166 000 km).
See ªScheduled Maintenance Servicesº in the Index.
Page 290 of 412

6-21
3. Check both sides of the dipstick, and read the lower
level. The fluid level must be in the COLD area,
below the cross
-hatched area, for a cold check or in
the HOT area or cross
-hatched area for a hot check.
4. If the fluid level is in the acceptable range, push the
dipstick back in all the way; then flip the handle
down to lock the dipstick in place.
How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission fluid to use. See ªRecommended
Fluids and Lubricantsº in the Index.Add fluid only after checking the transmission fluid
while it is hot. (A cold check is used only as a
reference.) If the fluid level is low, add only enough of
the proper fluid to bring the level up to the HOT area for
a hot check. It doesn't take much fluid, generally less
than one pint (0.5 L). Don't overfill.
NOTICE:
We recommend you use only fluid labeled
DEXRON-III, because fluid with that label is
made especially for your automatic transmission.
Damage caused by fluid other than
DEXRON
-III is not covered by your new
vehicle warranty.
After adding fluid, recheck the fluid level as
described under ªHow to Check.º
When the correct fluid level is obtained, push the
dipstick back in all the way; then flip the handle
down to lock the dipstick in place.
Page 359 of 412

Short Trip/City Scheduled Maintenance
7-20
48,000 Miles (80 000 km)
Change engine oil and filter (or every 3 months, whichever occurs first).
An Emission Control Service.
Lubricate chassis components (or every 3 months, whichever occurs first).
(See footnote #.)
Check axle fluid level and add fluid as needed. (See footnote **.)
Rotate tires. See ªTire Inspection and Rotationº in the Index for proper
rotation pattern and additional information. (See footnote +.)
Diesel Engine Only: Replace fuel filler cap if driving in dusty conditions.
An Emission Control Service.
50,000 Miles (83 000 km)
Change automatic transmission fluid and filter if the vehicle has a diesel
engine, if the vehicle's GVWR is over 8600 lbs. or if the vehicle is mainly
driven under one or more of these conditions:
± In heavy city traffic where the outside temperature regularly reaches
90F (32C) 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 fluid
and filter at 100,000 miles (166 000 km).
ACTUAL
SERVICED BY:MILEAGE
DATE
ACTUAL
SERVICED BY:MILEAGE
DATE
Page 370 of 412

Short Trip/City Scheduled Maintenance
7-31
99,000 Miles (165 000 km)
Change engine oil and filter (or every 3 months, whichever occurs first).
An Emission Control Service.
Lubricate chassis components (or every 3 months, whichever occurs first).
(See footnote #.)
Check axle fluid level and add fluid as needed. (See footnote **.)
100,000 Miles (166 000 km)
Gasoline Engine Only: Inspect spark plug wires.
An Emission Control Service.
Gasoline Engine Only: Replace spark plugs.
An Emission Control Service.
Change automatic transmission fluid and filter if the vehicle has a diesel
engine, if the vehicle's GVWR is over 8600 lbs. or if the vehicle is mainly
driven under one or more of these conditions:
± In heavy city traffic where the outside temperature regularly reaches
90F (32C) or higher.
± In hilly or mountainous terrain.
± When doing frequent trailer towing.
± Uses such as found in taxi, police or delivery service.
(Continued)
ACTUAL
SERVICED BY:MILEAGE
DATE
ACTUAL
SERVICED BY:MILEAGE
DATE
Page 371 of 412
Short Trip/City Scheduled Maintenance
7-32
100,000 Miles (166 000 km) (Continued)
If you haven't used your vehicle under severe service conditions listed
previously and, therefore, haven't changed your automatic transmission fluid,
change both the fluid and filter.
Gasoline Engine Only: Inspect Positive Crankcase Ventilation (PCV) valve.
An Emission Control Service.
150,000 Miles (240 000 km)
Drain, flush and refill cooling system (or every 60 months since last service,
whichever occurs first). See ªEngine Coolantº in the Index for what to use.
Inspect hoses. Clean radiator, condenser, pressure cap and neck. Pressure test
cooling system and pressure cap.
An Emission Control Service.ACTUAL
SERVICED BY:MILEAGE
DATE
Page 378 of 412

Long Trip/Highway Scheduled Maintenance
7-39
50,000 Miles (83 000 km)
Change automatic transmission fluid and filter if the vehicle has a diesel
engine, if the vehicle's GVWR is over 8600 lbs. or if the vehicle is mainly
driven under one or more of these conditions:
± In heavy city traffic where the outside temperature regularly
reaches 90F (32C) 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 fluid
and filter at 100,000 miles (166 000 km).
52,500 Miles (87 500 km)
Change engine oil and filter (or every 12 months, whichever occurs first).
An Emission Control Service.
Lubricate chassis components (or every 12 months, whichever occurs first).
(See footnote #.)
Check axle fluid level and add fluid as needed. (See footnote **.)
Rotate tires. See ªTire Inspection and Rotationº in the Index for proper
rotation pattern and additional information. (See footnote +.)
ACTUAL
SERVICED BY:MILEAGE
DATE
ACTUAL
SERVICED BY:MILEAGE
DATE