2002 CHEVROLET AVALANCHE service

2-121
Change Engine Oil
This message is displayed
when the engine oil needs to
be changed. The message
is only displayed for
15 seconds at the start of
each ignition cycle.
When you change the engine oil, be sure to reset the
Engine Oil Life Monitor. See ªEngine Oil, When to
Changeº in the Index.
Security
This message is
displayed when the
content theft
-deterrent
system has been activated
and also monitors the
Passlock

System.
If the security message is displayed continuously while
driving and stays on, there may be a problem with the
Passlock System. Your vehicle will not be protected by
Passlock, and you should see your GM dealer.
Service 4WD (If Equipped)
If the SERVICE 4WD
message comes on,
there may be a problem
with the automatic
transfer case and service
is required.
Malfunctions can be indicated by the system before
any problem is apparent, which may prevent serious
damage to the vehicle. This system is also designed
to assist your service technician in correctly diagnosing
a malfunction.

4-10
The Traction Assist System may operate on dry roads
under some conditions. When this happens, you may
notice a reduction in acceleration. This is normal and
doesn't mean there's a problem with your vehicle.
Examples of these conditions include a hard acceleration
in a turn, an abrupt upshift or downshift of the
transmission or driving on rough roads.
If your vehicle is in cruise control when the TAS begins
to limit wheel spin, the cruise control will automatically
disengage. When road conditions allow you to safely
use it again, you may re
-engage the cruise control.
See ªCruise Controlº in the Index.
When the TRACTION
OFF light is on, the TAS
is off and will not limit
wheel spin. Adjust your
driving accordingly.The TRACTION OFF light will come on under the
following conditions:

The Traction Assist System is turned off, either by
pressing the TAS on/off button or turning off the
automatic engagement feature of the TAS.

The transmission is in FIRST (1); TAS will not
operate in this gear. This is normal.

The vehicle is driven on an extremely rough road.
When the vehicle leaves the rough surface, slows
down or stops, the light will go off and TAS will
be on again. This is normal.

A Traction Assist System, Anti-Lock Brake System
or engine
-related problem has been detected and the
vehicle needs service.
See ªTraction Off Lightº in the Index.
The Traction Assist System, as delivered from the
factory, will automatically come on whenever you start
your vehicle. To limit wheel spin, especially in slippery
road conditions, you should always leave the system on.
But you can turn the TAS off if you ever need to.
You should turn the TAS off if your vehicle ever gets
stuck in sand, mud or snow and rocking the vehicle is
required. See ªRocking Your Vehicleº in the Index.

4-17
Off-Road Driving with Your
Four
-Wheel-Drive Vehicle
This off-road guide is for vehicles that have
four
-wheel drive.
Also, see ªAnti
-Lock Brakesº in the Index.
If your vehicle doesn't have four
-wheel drive, you
shouldn't drive off
-road unless you're on a level,
solid surface.
Off
-road driving can be great fun. But it does have
some definite hazards. The greatest of these is the
terrain itself.
ªOff
-roadingº means you've left the great North
American road system behind. Traffic lanes aren't
marked. Curves aren't banked. There are no road signs.
Surfaces can be slippery, rough, uphill or downhill.
In short, you've gone right back to nature.
Off
-road driving involves some new skills. And that's
why it's very important that you read this guide. You'll
find many driving tips and suggestions. These will help
make your off
-road driving safer and more enjoyable.
Before You Go Off-Roading
There are some things to do before you go out.
For example, be sure to have all necessary maintenance
and service work done. Check to make sure all
underbody shields (if so equipped) are properly
attached. Be sure you read all the information about
your four
-wheel-drive vehicle in this manual. Is there
enough fuel? Is the spare tire fully inflated? Are the
fluid levels up where they should be? What are the local
laws that apply to off
-roading where you'll be driving?
If you don't know, you should check with law
enforcement people in the area. Will you be on
someone's private land? If so, be sure to get the
necessary permission.

4-32 After Off-Road Driving
Remove any brush or debris that has collected
on the underbody, chassis or under the hood.
These accumulations can be a fire hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires and exhaust system
for damage. Also, check the fuel lines and cooling
system for any leakage.
Your vehicle will require more frequent service due to
off
-road use. Refer to the Maintenance Schedule for
additional information.
Driving at Night
Night driving is more dangerous than day driving. One
reason is that some drivers are likely to be impaired
-- by
alcohol or drugs, with night vision problems, or by fatigue.

4-39
The exit speed is usually posted.
Reduce your speed according to your speedometer, not
to your sense of motion. After driving for any distance
at higher speeds, you may tend to think you are going
slower than you actually are.
Before Leaving on a Long Trip
Make sure you're ready. Try to be well rested. If you
must start when you're not fresh
-- such as after a day's
work
-- don't plan to make too many miles that first part
of the journey. Wear comfortable clothing and shoes you
can easily drive in.
Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it's ready to go. If it needs
service, have it done before starting out. Of course,
you'll find experienced and able service experts in
Chevrolet dealerships all across North America.
They'll be ready and willing to help if you need it.Here are some things you can check before a trip:

Windshield Washer Fluid: Is the reservoir full?
Are all windows clean inside and outside?

Wiper Blades: Are they in good shape?

Fuel, Engine Oil, Other Fluids: Have you checked
all levels?

Lamps: Are they all working? Are the lenses clean?

Tires: They are vitally important to a safe,
trouble-free trip. Is the tread good enough for
long
-distance driving? Are the tires all inflated
to the recommended pressure?

Weather Forecasts: What's the weather outlook
along your route? Should you delay your trip a
short time to avoid a major storm system?

Maps: Do you have up
-to-date maps?

4-40
Highway Hypnosis
Is there actually such a condition as ªhighway hypnosisº?
Or is it just plain falling asleep at the wheel? Call it
highway hypnosis, lack of awareness, or whatever.
There is something about an easy stretch of road with
the same scenery, along with the hum of the tires on the
road, the drone of the engine, and the rush of the wind
against the vehicle that can make you sleepy. Don't let
it happen to you! If it does, your vehicle can leave the
road in less than a second, and you could crash and
be injured.
What can you do about highway hypnosis?
First, be aware that it can happen.
Then here are some tips:

Make sure your vehicle is well ventilated, with a
comfortably cool interior.

Keep your eyes moving. Scan the road ahead and
to the sides. Check your mirrors and your
instruments frequently.

If you get sleepy, pull off the road into a rest, service
or parking area and take a nap, get some exercise, or
both. For safety, treat drowsiness on the highway as
an emergency.
Hill and Mountain Roads
Driving on steep hills or mountains is different from
driving in flat or rolling terrain.

4-47 Dinghy Towing
(Two and Four-Wheel Drive Vehicles)
Tw o-Wheel-Drive Vehicles
Tw o
-wheel-drive, vehicles, should not be towed with
all four wheels on the ground. Two
-wheel-drive
transmissions have no provisions for internal lubrication
while being towed. To properly tow these vehicles, they
should be placed on a platform trailer with all four
wheels off the ground.
In rare cases when it's unavoidable that a two
-wheel
drive vehicle is to be towed with all four wheels on the
ground, the propeller shaft axle yoke orientation should
be marked and the propeller shaft removed following the
applicable service manual removal/installation procedure.
Dust or dirt can enter the back of the transmission
through the opening created by removing the propeller
shaft if proper protection is not provided. Also, check
the transmission fluid level before driving the truck.
When the vehicle is properly attached to the tow vehicle
and is ready to be towed, turn the ignition to OFF.
To prevent the battery from draining, remove the IGN 0
fuse from the instrument panel fuse block. See ªFusesº
in the Index for more information about removing the
IGN 0 fuse.

4-49 Dolly Towing
(Two-Wheel Drive Vehicle Only)
Tw o-Wheel Drive OnlyTw o
-Wheel-Drive Vehicles
Tw o
-wheel-drive, vehicles, should not be towed with
the rear wheels on the ground. Two
-wheel-drive
transmissions have no provisions for internal lubrication
while being towed. To properly tow these vehicles, they
should be placed on a platform trailer with all four
wheels off the ground.
In rare cases when it's unavoidable that a two
-wheel
drive vehicle is to be towed with the rear wheels on the
ground, the propeller shaft axle yoke orientation should
be marked and the propeller shaft removed following the
applicable service manual removal/installation procedure.
Dust or dirt can enter the back of the transmission
through the opening created by removing the propeller
shaft if proper protection is not provided. Also, check
the transmission fluid level before driving the truck.
When the vehicle is properly attached to the tow vehicle
and is ready to be towed, turn the ignition to LOCK.
Clamp the steering wheel in a straight
-ahead position
with a clamping device designed for towing.