2002 CHEVROLET AVALANCHE automatic transmission

4-60
Tow/Haul Mode
Tow/haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. The purpose of the
tow/haul mode is to:

Reduce the frequency and improve the predictability
of transmission shifts when pulling a heavy trailer or
a large or heavy load.

Provide the same solid shift feel when pulling a
heavy trailer or a large or heavy load as when the
vehicle is unloaded.

Improve control of vehicle speed while requiring less
throttle pedal activity when pulling a heavy trailer or
a large or heavy load.
Your vehicle is equipped with a button at the end of the
shift lever which when pressed enables tow/haul. When
the button is pressed, a light on the instrument panel will
illuminate to indicate that tow/haul has been selected.
Tow/haul may be turned off by pressing the button
again, at which time the indicator light on the instrument
panel will turn off. The vehicle will automatically turn
off tow/haul every time it is started.Tow/haul is designed to be most effective when
the vehicle and trailer combined weight is at least
75% of the vehicle's Gross Combined Weight Rating
(GCWR). See ªWeight of the Trailerº later in this
section. Tow/haul is most useful under the following
driving conditions:

When pulling a heavy trailer or a large or heavy load
through rolling terrain.

When pulling a heavy trailer or a large or heavy load
in stop and go traffic.

When pulling a heavy trailer or a large or heavy load
in busy parking lots where improved low speed
control of the vehicle is desired.
Operating the vehicle in tow/haul when lightly loaded or
with no trailer at all will not cause damage. However,
there is no benefit to the selection of tow/haul when the
vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission
driving characteristics and reduced fuel economy.
Tow/haul is recommended only when pulling a heavy
trailer or a large or heavy load.

4-68 Turn Signals When Towing a Trailer
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 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.
You can tow in DRIVE (D). You may want to shift the
transmission to THIRD (3) or, if necessary, a lower gear
selection if the transmission shifts too often (e.g., under
heavy loads and/or hilly conditions).
You may also want to activate the tow/haul mode if the
transmission shifts too often. See ªTow/Haul Modeº
in the Index.
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.

4-70 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.

5-4
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren't touching
each other. If they are, it could cause a ground
connection you don't want. You wouldn't be able
to start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake firmly on both vehicles involved
in the jump start procedure. Put an automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL before setting the parking brake.
If you have a four
-wheel-drive vehicle, be sure
the transfer case is not in NEUTRAL (N).
NOTICE:
If you leave your radio on, it could be badly
damaged. The repairs wouldn't be covered by
your warranty.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or in the accessory power outlets. Turn off the
radio and all lamps that aren't needed. This will
avoid sparks and help save both batteries. And it
could save your radio!
4. Open the hoods and locate the positive (+) and
negative (
-) terminal locations of the other vehicle.
Your vehicle has a remote positive (+) jump starting
terminal and a remote negative (
-) jump starting
terminal. You should always use these remote
terminals instead of the terminals on the battery.
The remote positive (+) terminal is located under
a red plastic cover near the engine accessory drive
bracket. To access the remote positive (+) terminal,
open the red plastic cover.
The remote negative (
-) terminal is located on the
engine accessory drive bracket and is marked ªGND.º
See ªEngine Compartment Overviewº in the Index
for more information on location.

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
6
-5 Fuels in Foreign Countries
6
-6 Filling Your Tank
6
-8 Checking Things Under the Hood
6
-12 Engine Oil
6
-18 Engine Air Cleaner/Filter
6
-20 Passenger Compartment Air Filter
6
-21 Automatic Transmission Fluid
6
-24 Rear Axle
6
-25 Four-Wheel Drive
6
-27 Engine Coolant
6
-30 Coolant Surge Tank Pressure Cap
6
-30 Power Steering Fluid
6
-32 Windshield Washer Fluid6
-33 Brakes
6
-37 Battery
6
-38 Bulb Replacement
6
-43 Windshield Wiper Blade Replacement
6
-44 Tires
6
-53 Appearance Care
6
-53 Cleaning the Inside of Your Vehicle
6
-57 Cleaning the Outside of Your Vehicle
6
-61 GM Vehicle Care/Appearance Materials
6
-62 Vehicle Identification Number (VIN)
6
-63 Electrical System
6
-71 Replacement Bulbs
6
-72 Capacities and Specifications
6
-73 Normal Maintenance Replacement Parts

6-10 Engine Compartment Overview
When you open the hood on the VORTEC 5300 V8 engine you will see the following:
A. Engine Air Cleaner/Filter
B. Coolant Surge Tank
C. Air Filter Restriction Indicator
D. Engine Oil Fill
E. Engine Oil DipstickF. Automatic Transmission Dipstick
G. Fan
H. Remote Negative (
-)
Terminal (GND)
I. Power Steering Fluid Reservoir
(Out of View)J. Remote Positive (+) Terminal
K. Brake Fluid Reservoir
L. Underhood Electrical Center
M. Battery
N. Windshield Washer Fluid Reservoir

6-11
When you open the hood on the VORTEC 8100 V8 engine you will see the following:
A. Engine Air Cleaner/Filter
B. Coolant Surge Tank
C. Air Filter Restriction Indicator
D. Engine Oil Dipstick
E. Automatic Transmission DipstickF. Engine Oil Fill
G. Fan
H. Remote Negative (
-)
Terminal (GND)
I. Remote Positive (+) TerminalJ. Power Steering Fluid Reservoir
K. Brake Fluid Reservoir
L. Underhood Electrical Center
M. Battery
N. Windshield Washer Fluid Reservoir

6-21
Automatic Transmission Fluid
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 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.
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 fluid can damage your
transmission. Too much can mean that some of
the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire.
Too little fluid could cause the transmission to
overheat. Be sure to get an accurate reading
if you check your transmission fluid.