2000 GMC YUKON ECU

3-30
A disc that has been ejected but is still sitting in the
remote CD player will be pulled back into the player
after approximately 30 seconds. This protects the disc
and player from damage. The disc will not start playing.
To remove the disc, press the EJECT button and remove
the disc from the player.
All of the compact disc functions are controlled by the
radio buttons except for EJECT. When a disc is in the
player, a CD symbol will appear on the display. When a
disc is playing, the letters CD will appear next to the CD
symbol in the bottom left corner. The track number will
also be displayed.
If the disc comes back out and ERR appears on the
display, it could be that:

The disc is upside down.

It is dirty, scratched or wet.

There's too much moisture in the air. (Wait about
an hour and try again.)

You are driving on a very rough road.
Please contact your dealership if any error recurs or
cannot be corrected.PREV (1): Press this button to go back to the start
of the current track if more than eight seconds have
played. Press PREV again to go to the previous track
on the disc.
NEXT (3): Press this button to advance to the next
track on the disc.
REV (4): Press and hold this button to quickly reverse
within a track. As the CD reverses, elapsed time will be
displayed to help you find the correct passage.
FWD (6): Press and hold this button to quickly advance
within a track. As the CD advances, elapsed time will be
displayed to help you find the correct passage.
SEEK: Press the left arrow while playing a CD to
go back to the start of the current track. It will go
back to the current track if more than eight seconds
have played. Press the left arrow again to go to previous
tracks. Press the right arrow to go to the next higher
track on the disc.

3-32
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 buttons 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.
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.

3-33
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 buttons 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.
Press HR to make the first one or two digits agree with
your code.
6. 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
3. Pull the push-pins and
lower air dam assembly
away from the retainers
until the lower air dam
is free.
When you're back on roads, though, be sure to replace
the air dam.
NOTICE:
Operating your vehicle for extended periods
without the front bumper lower air dam installed
can cause improper air flow to the engine and
may allow things like fog lamps or tow hooks
on the front of your vehicle to be damaged.
Always be sure to replace the front bumper
air dam when you're finished off
-road driving.
To replace the lower air dam:
1. Line up each push-pin
with its intended retainer
and push the washer
portion of the push
-pin
towards the retainer until
it locks into place
2. Push the flat end of the
push
-pin towards the
retainer until it locks
into place, making sure
each is secure.

4-19 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 Driving
Here 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.

4-45 Four-Wheel-Drive Vehicles
CAUTION:
Shifting the transfer case into NEUTRAL (N) can
cause your vehicle to roll even if the transmission
is in PARK (P), for an automatic transmission.
You or others could be injured. Make sure the
parking brake is firmly set before you shift the
transfer case into NEUTRAL (N).

Firmly set the parking brake.

Shift the transmission to PARK (P).
Securely attach the vehicle being towed to
the tow vehicle.

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.

Release the parking brake only after the
vehicle being towed is firmly attached to the
towing vehicle.

Turn the ignition to OFF. The OFF position
unlocks the steering column and reduces battery
drain as long as the IGN 0 fuse is removed.
Unlocking the steering column will allow the
proper movement of the front wheels and tires
during towing.

4-47
NOTICE:
Some vehicles may be equipped with RPO VYU
(snow plow prep package). With this option, the
payload your vehicle can carry is reduced when
a snow plow is installed. Your vehicle can be
damaged if either the front or rear axle ratings,
or the GVW are exceeded.
As a general guideline, with a 650 lb. (295 kg)
snow plow, the weight of the occupants and cargo
must not exceed 300 lb. (135 kg). However, this
may depend on the vehicle's option content.
Therefore, to help avoid vehicle damage:

Make sure the weight on the front and
rear axles does not exceed their respective
axle ratings.
NOTICE: (Continued)
NOTICE: (Continued)

For the front axle, if more cargo or
passengers need to be carried, appropriate
counter ballast must be installed rear of
the rear axle and properly secured.

Total vehicle weight must not exceed the
GVW rating.

See your dealer for advice and information
about using a snow plow on your vehicle.
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.