2002 CHEVROLET BLAZER ECU

3-71
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 at the same time. 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 knob will begin
flashing when the ignition is turned off.

3-72
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 at the same time.
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.

3-73
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.
Theft-Deterrent Feature RDS Radios
(If Equipped)
THEFTLOCK
is designed to discourage theft of your
radio. The feature works automatically by learning a
portion of the Vehicle Identification Number (VIN).
If the radio is moved to a different vehicle, it will not
operate and LOCKED or LOC will be displayed.
When the radio and vehicle are turned off, the blinking
red light indicates that THEFTLOCK is armed.
With THEFTLOCK activated, your radio will not
operate if stolen.
Audio Steering Wheel Controls
(If Equipped)
If your vehicle has this feature, you can control certain
radio functions using the buttons on your steering wheel.
PROG (Program): Press this button to go to a station
you have programmed on the radio preset buttons on the
selected band. If a cassette tape is playing, press this
button to play the other side of the tape. If a compact
disc is playing in the console
-mounted CD changer
(if equipped), press this button to go to the next
available CD.

4-16 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.
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.

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.

4-40
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.
Driving on Snow or Ice
Most of the time, those places where your tires meet the
road probably have good traction.
However, if there is snow or ice between your tires and
the road, you can have a very slippery situation. You'll
have a lot less traction or ªgripº and will need to be
very careful.

4-49
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.
Payload
The payload capacity is shown on the Certification/Tire
label. This is the maximum load capacity that your
vehicle can carry. Be sure to include the weight of the
occupants as part of your load. If you added any
accessories or equipment after your vehicle left the
factory, remember to subtract the weight of these things
from the payload. Your dealer can help you with this.
Add-On Equipment
When you carry removable items, you may need to put a
limit on how many people you carry inside your vehicle.
Be sure to weigh your vehicle before you buy and install
the new equipment.
NOTICE:
Your warranty doesn't cover parts or
components that fail because of overloading.

4-58 Driving with a Trailer
CAUTION:
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon monoxide
(CO) could come into your vehicle. You can't see
or smell CO. It can cause unconsciousness or
death. See ªEngine Exhaustº in the Index. To
maximize your safety when towing a trailer:

Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.

Keep the rear
-most windows closed.

If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main heating
or cooling system on and with the fan on
any speed. This will bring fresh, outside air
into your vehicle. Do not use MAX A/C or
RECIRCULATION because it only
recirculates the air inside your vehicle.
See ªComfort Controlsº in the Index.
Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you'll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the
trailer. And always keep in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check the trailer hitch and platform
(and attachments), safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer has
electric brakes, start your vehicle and trailer moving and
then apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer brakes
are still working.

4-63 Trailer Wiring Harness
The light-duty trailer wiring is a six-wire harness
assembly. The optional heavy
-duty trailer wiring is an
eight
-wire harness assembly. The harnesses are stored
under the vehicle, along the passenger
-side frame
crossmember on two
-door vehicles or on the driver's
side corner frame rear crossmember on four
-door
vehicles. The heavy
-duty trailer wiring is fused in the
engine compartment fuse block. See ªFuses and
Circuit Breakersº in the Index. Both harnesses have
no connector 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.
Dark Blue: Use for electric trailer brakes or auxiliary
wiring (eight
-wire harness only).

Red: Use for battery charging; it connects to the
starter solenoid (eight
-wire harness only).

Light Green: Back
-up lamps.

Brown: Taillamps and parking lamps.

Yellow: Driver's side stoplamp and turn signal.

Dark Green: Passenger's side stoplamp and
turn signal.

White: Ground wire.

Light Blue: Auxiliary stoplamp.
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.