2001 CHEVROLET TAHOE ECU

2-15 Testing the Alarm
The alarm can be tested by following these steps:
1. From inside the vehicle, lower the driver's window
and open the driver's door.
2. Activate the system by locking the doors with the
power door lock switch while the door is open, or
with the remote keyless entry transmitter.
3. Get out of the vehicle, close the door and wait for the
SECURITY message to go out.
4. Then reach in through the window, unlock the
door with the manual door lock and open the door.
This should set off the alarm.
If the alarm does not sound when it should but the
vehicle's headlamps flash, check to see if the horn
works. The horn fuse may be blown. To replace the fuse,
see ªFuses and Circuit Breakersº in the Index.
If the alarm does not sound or the vehicle's headlamps
do not flash, the vehicle should be serviced by an
authorized service center.
Passlock

Your vehicle is equipped with the Passlock
theft
-deterrent system.
Passlock is a passive theft
-deterrent system. Passlock
enables fuel if the ignition lock cylinder is turned with a
valid key. If a correct key is not used or the ignition lock
cylinder is tampered with, fuel is disabled.
If the engine stalls and the SECURITY message flashes,
wait until the light stops flashing before trying to restart
the engine. Remember to release the key from START
as soon as the engine starts.
If the engine is running and the SECURITY message
comes on, you will be able to restart the engine if you turn
the engine off. However, your Passlock system is not
working properly and must be serviced by your dealer.
Your vehicle is not protected by Passlock at this time. You
may also want to check the fuse (see ªFuses and Circuit
Breakersº in the Index). See your dealer for service.
In an emergency, call the GM Roadside Assistance
Center. See ªRoadside Assistanceº in the Index.

2-55 Cargo Security Shade (If Equipped)
CAUTION:
An improperly stored cargo cover could be
thrown about the vehicle during a collision or
sudden maneuver. You or others could be
injured. If you remove the cover, always store it
outside of the vehicle. When you put it back,
always be sure that it is securely reattached.
If you have a cargo security shade, you can use it to
cover items in the cargo area of your vehicle.
To use the shade, pull the shade handle toward the rear
of the vehicle. Latch the shade posts into the retaining
sockets on the cargo area trim panels.
To return the shade to the retracted position, pull up on
the shade handle to release the shade posts from the
retaining sockets. Let the shade move forward to the full
retracted position.To remove the shade from the vehicle, first let the shade
go all the way into the holder. Then, grasping the
passenger's side shade endcap, push the shade endcap
toward the driver's side of the vehicle. The endcap
should lock in the compressed position. Lift the shade
up on the passenger's side, swing the shade rearward
and take it out of the vehicle.
To put the shade in the vehicle, first make sure the shade
slot in the holder faces rearward with the round surface
facing down. Then, hold the shade at an angle and place
the shade holder tab into the slot in the driver's side trim
panel. Move the other end of the shade forward and hold
it next to the passenger's side trim panel slot.
Push the button on top of the passenger's side endcap.
This will allow the shade to extend into the trim slot.
Lightly pull on the shade holder to make sure it is
secure. On Suburban/Yukon XL models there are
two slots. The slots furthest forward allow the shade to
be used if the third seat is removed or folded down.

2-56 Cargo Tie Downs
There are cargo tie downs
in the rear cargo area that
allow you to strap cargo in
and keep it from moving
inside the vehicle.
When not using the tie downs, flip them down out of
the way.
Convenience Net (If Equipped)
You may have a convenience net in the rear of your
vehicle to help keep small loads, like grocery bags, in
place during sharp turns or quick stops and starts.
The net is not designed for larger, heavier items.
To install the net, attach the hooks to the raised cargo
tie downs. Then, attach the cord loops to the button
retainers in the side trim.
You can unhook the net so that it will lie flat when
you're not using it.
Luggage Carrier (If Equipped)
If you have the luggage carrier, you can load things on
top of your vehicle.
The luggage carrier has slats and siderails attached to
the roof and crossrails which can be moved back and
forth to help secure cargo. Tie the load to the siderails
or siderail supports.
NOTICE:
Loading cargo that weighs more than
200 lbs. (90.6 kg) on the luggage carrier may
damage your vehicle. When you carry large
things, never let them hang over the rear or the
sides of your vehicle. Load your cargo so that it
rests on the slats and does not scratch or damage
the vehicle. Put the cargo against the siderails
and fasten it securely to the luggage carrier.
Don't exceed the maximum vehicle capacity when loading
your vehicle. For more information on vehicle capacity
and loading, see ªLoading Your Vehicleº in the Index.

2-57
To prevent damage or loss of cargo as you're leaving,
check now and then to make sure the luggage and cargo
are still securely fastened.
Be sure the cargo is properly loaded.

If small heavy objects are placed on the roof, place
the load in the area over the rear wheels (behind the
rear side door on Suburban/Yukon XL Models).
If you need to, cut a piece of 3/8 inch plywood to fit
inside the crossrails and siderails to spread the load.
If plywood is used, tie it to the siderail supports.

Tie the load to the crossrails or the siderail supports.
Use the crossrails only to keep the load from sliding.
To move the crossrails, pull out on the latch release
handle at each end. Slide the crossrail to the desired
position balancing the force side to side. Push the
release handle back into the latched position and
slide the crossrail back and forth slightly to be sure
the latch snaps securely into place.
If you need to carry long items, move the crossrails
as far apart as they will go. Tie the load to the
crossrails and the siderails or siderail supports. Also
tie the load to the bumpers. Do not tie the load so
tightly that the crossrails or siderails are damaged.

For the purpose of wind noise reduction, locate the
front crossrail approximately 18 to 24 inches
(46 cm to 58 cm) rearward of the front supports.

After moving a crossrail, be sure it is securely locked
into the siderail.
Your vehicle has a Center High
-Mounted
Stoplamp (CHMSL) located above the glass or above
the rear load doors.
If items are loaded on the roof of the vehicle,
care should be taken not to block or damage the
CHMSL unit.

2-64
Call ANSWER/END Button: Use this button
to answer a call. (If you are receiving a call, the audio
system will mute, and the ring will be heard). Press this
button at the end of a call to disconnect and return the
audio system to its previous settings. This button will
also cancel a call if one of the buttons is accidentally
pressed or if the automatic redial function is activated.
Volume Control: You can control the volume of the
OnStar System using either the volume control knob on
the radio or using the steering wheel controls, if equipped.
Telltale Light: This light will indicate the status of
the system. A solid green light will come on when you
start the vehicle to let you know that the system is on
and is ready to make or receive calls.
If the light blinks green it means that an incoming
or outgoing call is in progress. Press the Call
ANSWER/END button if you notice the light blinking
and you are not on a call.
The light will be red in the event of an OnStar system
malfunction. If this occurs press the OnStar button to
attempt to contact an advisor. If the connection is made,
the advisor will assist you with steps to take to make
sure that the system is functioning properly. If you
cannot contact the advisor, take your vehicle to your
dealership as soon as possible for assistance.
Safety and Security Services

Automatic Notification of Air Bag
Deployment
-- If an air bag deploys, a priority
emergency signal is sent automatically to the center.
An advisor will locate your vehicle's position, try to
contact you and assist you in the situation. If the
center is unable to contact you, an emergency service
provider will be contacted.

Stolen Vehicle Tracking
-- Call the center at
1
-888-4-ONSTAR (1-888-466-7827) to report your
vehicle stolen. The system can then locate and track
your vehicle and the advisor will be able to notify
the proper authorities.

Roadside Assistance with Location
-- For vehicle
breakdowns, press the OnStar button. An advisor
will contact the appropriate help.

Remote Diagnostics
-- If an instrument panel light
comes on, the center can perform a check of the
engine on
-board computer. An advisor can then
recommend what action needs to be taken.

OnStar MED
-NET -- Med-Net can store your
personal medical history and provide it to emergency
personnel if necessary.

Accident Assist
-- An advisor can provide
step
-by-step guidance following an accident.

2-65

Remote Door Unlock -- To contact the center,
call 1
-888-4-ONSTAR. You will be required to
provide your security information. An advisor will
send a command to your vehicle to unlock itself.
The advisor can delay unlocking your vehicle.
Remote Door Unlock is disabled 48 hours after the
vehicle is parked to maintain the battery charge.

Vehicle Locator Service
-- To contact the center,
call 1
-888-4-ONSTAR. You will be required to
provide your security information. An advisor will
send a command to your vehicle to sound the horn
and/or flash the lamps.
In order to provide you with excellent service, calls with
the OnStar Center may be monitored or recorded.
Premium Services (Includes Safety and
Security Services)

Route Support -- An advisor can provide directions
or guidance to anywhere you want to go. In addition,
they can help you locate gas stations, rest areas,
ATMs, hospitals, hotels, stores, eateries and more.

Concierge Services
-- The concierge advisor can
obtain tickets, reservations or help with vacation/trip
planning and other unique items and services.

Ride Assist
-- An advisor can locate transportation
in the event that you are unable to drive.
OnStar System Limitations
Complete limitations can be found on the subscriber
services agreement.
OnStar Service is:

available in the 48 contiguous United States, Alaska,
Hawaii and Canada;

available when the vehicle is within the operating
range of a cellular provider;

subject to limitations caused by atmospheric
conditions, such as severe weather or topographical
conditions, such as mountainous terrain.

subject to cellular carrier equipment limitations.
Global positioning capabilities used to deliver service
will not be available if satellite signals are obstructed.
OnStar will not function if the vehicle's battery is
discharged or disconnected. It may also be inoperative
if the vehicle is in an accident and the OnStar or vehicle
electrical system components are damaged.
Safety and security services are provided by existing
governmental emergency service providers. OnStar will
use reasonable efforts to contact the appropriate
emergency service provider and request assistance but
cannot promise that they will respond to the call in a
timely manner or at all.

2-89 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 System. See ªEngine Oil, When to
Changeº in the Index.
Security
This message is displayed
when the content
theft
-deterrent system
(if equipped) 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.

3-31 Theft-Deterrent Feature (If Equipped)
THEFTLOCK
is designed to discourage theft of your
radio. It works by using a secret code to disable all radio
functions whenever battery power is removed.
The THEFTLOCK feature for the radio may be used or
ignored. If ignored, the system plays normally and the
radio is not protected by the feature. If THEFTLOCK
is activated, your radio will not operate if stolen.
When THEFTLOCK is activated, the radio will display
LOC to indicate a locked condition anytime battery
power has been interrupted. If your battery loses power
for any reason, you must unlock the radio with the secret
code before it will operate.
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.