2002 CHEVROLET AVALANCHE ECU

3-18
Activating the Theft-Deterrent Feature
The instructions which follow explain how to enter
your secret code to activate the THEFTLOCK system.
It is recommended that you read through all nine steps
before starting the procedure.
If you allow more than 15 seconds to elapse between
any steps, the radio automatically reverts to time and
you must start the procedure over at Step 4.
1. Write down any three or four
-digit number
from 000 to 1999 and keep it in a safe place
separate from the vehicle.
2. Turn the ignition to ACCESSORY or RUN.
3. Turn the radio off.
4. Press the 1 and 4 pushbuttons together. Hold them
down until
--- shows on the display. Next you
will use the secret code number which you have
written down.5. Press MN and 000 will appear on the display.
6. Press MN again to make the last two digits agree
with your code.
7. Press HR to make the first one or two digits agree
with your code.
8. Press AM FM after you have confirmed that the
code matches the secret code you have written down.
The display will show REP to let you know that you
need to repeat Steps 5 through 7 to confirm your
secret code.
9. Press AM FM and this time the display will show
SEC to let you know that your radio is secure.
The LED indicator by the volume control will begin
flashing when the ignition is turned off.

3-19
Unlocking the Theft-Deterrent Feature After a
Power Loss
Enter your secret code as follows; pause no more than
15 seconds between steps:
1. Turn the ignition on. LOC will appear on the display.
2. Press MN and 000 will appear on the display.
3. Press MN again to make the last two digits agree
with your code.
4. Press HR to make the first one or two digits agree
with your code.
5. Press AM FM after you have confirmed that the
code matches the secret code you have written down.
The display will show SEC, indicating the radio is
now operable and secure.
If you enter the wrong code eight times, INOP will
appear on the display. You will have to wait an hour
with the ignition on before you can try again. When you
try again, you will only have three chances to enter the
correct code before INOP appears.
If you lose or forget your code, contact your dealer.Disabling the Theft-Deterrent Feature
Enter your secret code as follows; pause no more than
15 seconds between steps:
1. Turn the ignition to ACCESSORY or RUN.
2. Turn the radio off.
3. Press the 1 and 4 pushbuttons together. Hold them
down until SEC shows on the display.
4. Press MN and 000 will appear on the display.
5. Press MN again to make the last two digits agree
with your code.
6. Press HR to make the first one or two digits agree
with your code.
7. Press AM FM after you have confirmed that the
code matches the secret code you have written down.
The display will show
---, indicating that the radio
is no longer secured.
If the code entered is incorrect, SEC will appear on the
display. The radio will remain secured until the correct
code is entered.
When battery power is removed and later applied to a
secured radio, the radio won't turn on and LOC will
appear on the display.
To unlock a secured radio, see ªUnlocking the
Theft
-Deterrent Feature After a Power Lossº earlier
in this section.

4-18 Loading Your Vehicle for Off-Road Driving
There are some important things to remember about
how to load your vehicle.

The heaviest things should be on the load floor and
forward of your rear axle. Put heavier items as far
forward as you can.

Be sure the load is secured properly, so driving on
the off
-road terrain doesn't toss things around.
CAUTION:

Cargo on the load floor piled higher than
the seatbacks can be thrown forward
during a sudden stop. You or your
passengers could be injured. Keep cargo
below the top of the seatbacks.
CAUTION: (Continued)
CAUTION: (Continued)

Unsecured cargo on the load floor can be
tossed about when driving over rough
terrain. You or your passengers can be
struck by flying objects. Secure the
cargo properly.

Heavy loads on the roof raise the vehicle's
center of gravity, making it more likely to
roll over. You can be seriously or fatally
injured if the vehicle rolls over. Put heavy
loads inside the cargo area, not on the roof.
Keep cargo in the cargo area as far forward
and low as possible.
You'll find other important information in this manual.
See ªVehicle Loading,º ªLuggage Carrierº and ªTiresº
in the Index.

4-42
Winter DrivingHere are some tips for winter driving:

Have your vehicle in good shape for winter.

You may want to put winter emergency supplies in
your vehicle.
Include an ice scraper, a small brush or broom, a supply
of windshield washer fluid, a rag, some winter outer
clothing, a small shovel, a flashlight, a red cloth and
reflective warning triangles. And, if you will be driving
under severe conditions, include a small bag of sand, a
piece of old carpet or a couple of burlap bags to help
provide traction. Be sure you properly secure these
items in your vehicle.

4-48
Four-Wheel-Drive Vehicles
Use the following procedure to correctly tow your
vehicle on all four wheels:
1. Firmly set the parking brake.
2. Shift the transmission to PARK (P).
3. Securely attach the vehicle being towed to the
tow vehicle.
CAUTION:
Shifting a four-wheel-drive vehicle's transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in Park (P). You or
others could be injured. Make sure the parking
brake is firmly set before you shift the transfer
case to NEUTRAL. See ªTransfer Caseºin the
Index for more information.
4. Shift the transfer case to NEUTRAL (N).
See ªFour
-Wheel-Driveº in the Index for the
proper procedure to select the neutral position for
your vehicle.
5. Release the parking brake only after the vehicle
being towed is firmly attached to the towing vehicle.
6. 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.

4-51
Loading Your Vehicle
The Certification/Tire label is found on the rear edge of
the driver's door or in the Incomplete Vehicle Document
in the cab.
The label shows the size of your original tires and the
inflation pressures needed to obtain the gross weight
capacity of your vehicle. This is called the GVWR
(Gross Vehicle Weight Rating). The GVWR includes
the weight of the vehicle, all occupants, fuel and cargo.The Certification/Tire label also tells you the maximum
weights for the front and rear axles, called Gross Axle
Weight Rating (GAWR). To find out the actual loads
on your front and rear axles, you need to go to a weigh
station and weigh your vehicle. Your dealer can help
you with this. Be sure to spread out your load equally
on both sides of the centerline.
Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
The Certification/Tire label also contains information
about your Front Axle Reserve Capacity. See ªFront
Axle Reserve Capacityº later in this section.
And, if you do have a heavy load, you should spread
it out.CAUTION:
In the case of a sudden stop or collision, things
carried in the bed of your truck could shift
forward and come into the passenger area,
injuring you and others. If you put things in
the bed of your truck, you should make sure
they are properly secured.

4-52
CAUTION:
Do not load your vehicle any heavier than the
GVWR, or either the maximum front or rear
GAWR. If you do, parts on your vehicle can
break, and it can change the way your vehicle
handles. These could cause you to lose control
and crash. Also, overloading can shorten the
life of your vehicle.
Your warranty does not cover parts or components that
fail because of overloading.
This will help you decide how much cargo and installed
equipment your truck can carry.
Using heavier suspension components to get added
durability might not change your weight ratings. Ask
your dealer to help you load your vehicle the right way.
If you put things inside your vehicle
-- like suitcases,
tools, packages, or anything else
-- they go as fast as
the vehicle goes. If you have to stop or turn quickly,
or if there is a crash, they'll keep going.
CAUTION:
Things you put inside your vehicle can strike
and injure people in a sudden stop or turn,
or in a crash.

Put things in the cargo area of your vehicle.
Try to spread the weight evenly.

Never stack heavier things, like suitcases,
inside the vehicle so that some of them are
above the tops of the seats.

Don't leave an unsecured child restraint
in your vehicle.

When you carry something inside the
vehicle, secure it whenever you can.

Don't leave a seat folded down unless
you need to.
There's also important loading information for off-road
driving in this manual. See ªLoading Your Vehicle for
Off
-Road Drivingº in the Index.

4-54
Q:How do I know if my vehicle can handle a
snow plow?
A:Some vehicles are built with a special package,
called RPO VYU (snow plow prep package).
If your vehicle has this option, you can add a
plow to it, provided certain weights, such as the
weights on the vehicle's axles and the GVW,
aren't exceeded.
Q:How heavy can a snow plow safely be?
A:The plow your vehicle can carry depends on many
things, such as:

The options your vehicle came with, and the
weight of those options,

The weight and number of passengers you intend
to carry,

The weight of items you've added to your
vehicle, like a tool box or truck cap,

The total weight of any additional cargo you
intend to carry.
Say, for example, you have a 700 lb. (318 kg) snow
plow. The total weight of all occupants and cargo
inside the cab should not exceed 300 lb. (135 kg).This means that you may only be able to carry
one passenger. But, even this may be too much if
you've got other equipment already adding to the
weight of your vehicle.
Here are some guidelines for safely carrying a snow
plow on your vehicle:

Make sure the weight on the front and rear axles
doesn't exceed the axle rating for each.

For the front axle, if more cargo or passengers must
be carried, appropriate counter ballast must be
installed rear of the rear axle. Counter ballast must
be properly secured so it won't move during driving.

Follow the snow plow manufacturer's
recommendations regarding rear ballast. Rear ballast
may be required to ensure a proper front and rear
weight distribution ratio, even though the actual
weight at the front axle may be less than the front
axle rating.

The snow plow manufacturer or installer can assist
you in determining the amount of rear ballast
required, to help make sure your snowplow/vehicle
combination does not exceed the GVW rating, the
front and rear axle ratings, and the front and rear
weight distribution ratio.

The total vehicle must not exceed the GVW rating.