2002 GMC YUKON XL engine

2-30Locking Rear Axle Your locking rear axle can give you additional traction
on snow, mud, ice, sand or gravel. It works like a
standard axle most of the time, but when one of the rear
wheels has no traction and the other does, this feature
will allow the wheel with traction to move the vehicle.
All -
Wheel DriveWith this feature, engine power is sent to all four wheels
when extra traction is needed.
This is like four
- wheel drive, but there is no separate
lever or switch to engage or disengage the front axle.
It is fully automatic, and adjusts itself as needed for
road conditions.
Horn To sound the horn, press the center pad on the
steering wheel. Tilt Wheel The tilt steering wheel allows you to adjust the steering
wheel before you drive. You can raise it to the highest
level to give your legs more room when you enter and
exit the vehicle.
The tilt lever is located
on the driver's side of the
steering column under
the turn signal lever.
To tilt the wheel, hold the steering wheel and pull the
lever. Move the steering wheel to a comfortable level,
then release the lever to lock the wheel in place.

2-39Puddle Lamps Your vehicle is equipped with puddle lamps to help you
see the area near the base of the front doors when it is
dark out. The puddle lamps will illuminate when a door
is opened or when you press the UNLOCK button on the
keyless entry transmitter. The lamps will time out or
turn off once the engine is started.
You can program the puddle lamps not to come on if
you choose. See ªSecondary Information Centerº in the
Index for more information.
Daytime Running Lamps Daytime Running Lamps (DRL) can make it easier
for others to see the front of your vehicle during the
day. DRL can be helpful in many different driving
conditions, but they can be especially helpful in the
short periods after dawn and before sunset. Fully
functional daytime running lamps are required on all
vehicles first sold in Canada. The DRL system will come on when:

The ignition is on,

the exterior lamps control is off,

the automatic transmission is not in PARK (P),

the light sensor determines it is daytime and

the parking brake is released.
When the DRL are on, only your DRL lamps will be on.
The taillamps, sidemarker and other lamps won't be on.
The instrument panel won't be lit up either.
When it begins to get dark, the automatic headlamp
system will switch from DRL to the headlamps or the
last chosen headlamp setting that was used.
When you turn the exterior lamps control to the off
position, the headlamps will go off, and your DRL
lamps will illuminate, provided it is not dark outside.
To idle your vehicle with the DRL off, set the parking
brake. Shifting the transmission into PARK (P) will also
allow you to idle the vehicle with the DRL off. The
DRL will stay off until you release the parking brake
or shift the transmission out of PARK (P).

2-55Volume Control: You can control the volume of the
OnStar System using either the volume 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 Communication
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 Services
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.
Cellular Antenna: The cellular antenna on the outside
of your vehicle is critical to effective communications
using the OnStar system. Optimum cellular reception
can be obtained when the mast is straight up and down. OnStar Services The following services are available within OnStar
service plans. Your vehicle comes with a specific
one
- year service plan that allows use of some or all
of the following 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 attempt to locate
and track your vehicle and the advisor will assist the
proper authorities.

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

Remote Diagnostics: If an instrument panel
light comes on, press the OnStar Services button.
An advisor can perform a check of the engine
on
- board computer, and recommend what action
needs to be taken.

2-59Programming the HomeLink Transmitter Do not use the HomeLink Transmitter with any garage
door opener that does not have the stop and reverse
feature. This includes any garage door opener model
manufactured before April 1, 1982.
Be sure that people and objects are clear of the garage
door you are programming.
It is recommended that a new battery be installed in
your hand
- held transmitter for quicker and more
accurate transmission of the radio frequency.
Your vehicle's engine should be turned off while
programming the transmitter. Follow these steps to
program up to three channels:
1. Decide which one of the three channels (one of the
HomeLink buttons) you want to program.
2. Press and hold the desired button on HomeLink
through Step 3. 3. When the HomeLink indicator light begins to blink
slowly (this may take up to 30 seconds), hold the
hand
- held transmitter about 1 to 3 inches (3 to 8 cm)
away from HomeLink and then press and hold the
transmit button on the hand
- held transmitter.
Continue to hold both buttons until the indicator
light on HomeLink begins to flash rapidly (this may
take up to 90 seconds).
If you have trouble programming HomeLink, make
sure that you have followed the directions exactly as
described and that the battery in the hand
- held
transmitter is not weak. If you still cannot program it,
move the hand
- held transmitter to the left or right or
forward or backward or flip it upside down. HomeLink
may not work with older garage door openers that do
not meet current Federal Consumer Safety Standards.
If you cannot program the transmitter after repeated
attempts, refer to ªTraining a Garage Door Opener with
Rolling Codesº later in this section or contact the
manufacturer of HomeLink at 1
- 800
- 355
- 3515,
or on the internet at www.homelink.com.
Be sure to keep the original hand
- held transmitter in
case you need to erase and reprogram HomeLink.

2-65Speedometer and Odometer Your speedometer lets you see your speed in both
miles per hour (mph) and kilometers per hour (km/h).
Your odometer shows how far your vehicle has been
driven, in either miles (used in the United States) or
kilometers (used in Canada).
Trip Odometer
The trip odometer can tell you how far your vehicle has
been driven since you last set the trip odometer to zero.
Press the reset button to toggle between the trip
odometer and the regular odometer. Holding the reset
button for two seconds while the trip odometer is
displayed will reset it.
To display the odometer reading with the ignition off,
press the reset button.
Engine Hour Meter Display
The odometer can also display the number of hours the
engine has run. To display the hour meter, turn the
ignition off, press and hold the reset button for at least
four seconds. The hour meter will be displayed for up to
30 seconds, or until the ignition is turned on. Tachometer Your tachometer displays the engine speed in
revolutions per minute (rpm).
Warning Lights, Gages
and Indicators This part describes the warning lights and gages on your
vehicle. The pictures will help you locate them.
Warning lights and gages can signal that something is
wrong before it becomes serious enough to cause an
expensive repair or replacement. Paying attention to
your warning lights and gages could also save you or
others from injury.
Warning lights come on when there may be or is a
problem with one of your vehicle's functions. As you
will see in the details on the next few pages, some
warning lights come on briefly when you start the
engine just to let you know they're working. If you are
familiar with this section, you should not be alarmed
when this happens.
Gages can indicate when there may be or is a problem
with one of your vehicle's functions. Often gages and
warning lights work together to let you know when
there's a problem with your vehicle.

2-67CAUTION:If the air bag readiness light stays on after you
start your vehicle, it means the air bag system
may not be working properly. The air bags in
your vehicle may not inflate in a crash, or they
could even inflate without a crash. To help avoid
injury to yourself or others, have your vehicle
serviced right away if the air bag readiness light
stays on after you start your vehicle.
The air bag readiness light should flash for a few
seconds when you turn the ignition key to RUN. If the
light doesn't come on then, have it fixed so it will be
ready to warn you if there is a problem. Voltmeter
United States Canada
When your engine is not running, but the ignition is in
RUN, this gage shows your battery's state of charge in
DC volts.
When the engine is running, the gage shows the
condition of the charging system. Readings between
the low and high warning zones indicate the normal
operating range.

2-68 Readings in the low warning zone may occur when a
large number of electrical accessories are operating
in the vehicle and the engine is left at an idle for an
extended period. This condition is normal since the
charging system is not able to provide full power at
engine idle. As engine speeds are increased, this
condition should correct itself as higher engine speeds
allow the charging system to create maximum power.
You can only drive for a short time with the reading
in either warning zone. If you must drive, turn off all
unnecessary accessories.
Readings in either warning zone indicate a possible
problem in the electrical system. Have the vehicle
serviced as soon as possible.
Brake System Warning Light With the ignition on, the brake system warning light
will flash when you set the parking brake. The light
will flash if the parking brake doesn't release fully. If
you try to drive with the parking brake engaged, a
chime will sound when the vehicle speed is greater than
3 mph (5 km/h). Your vehicle's hydraulic brake system is divided into
two parts. If one part isn't working, the other part can
still work and stop you. For good braking, though, you
need both parts working well.
If the warning light comes on, there could be a brake
problem. Have your brake system inspected right away.
United States Canada
This light should come on briefly when you turn the
ignition key to RUN. If it doesn't come on then,
have it fixed so it will be ready to warn you if there's
a problem.

2-69If the light comes on while you are driving, pull off the
road and stop carefully. You may notice that the pedal is
harder to push. Or, the pedal may go closer to the floor.
It may take longer to stop. If the light is still on, have the
vehicle towed for service. See ªTowing Your Vehicleº in
the Index.
CAUTION:Your brake system may not be working properly
if the brake system warning light is on. Driving
with the brake system warning light on can lead
to an accident. If the light is still on after you've
pulled off the road and stopped carefully, have
the vehicle towed for service. Anti-Lock Brake System Warning Light With the anti
- lock brake
system, this light will come
on when you start your
engine and may stay on
for several seconds.
That's normal.
If the light stays on, or comes on when you're driving,
your vehicle needs service. If the regular brake system
warning light isn't on, you still have brakes, but you
don't have anti
- lock brakes. If the regular brake system
warning light is also on, you don't have anti
- lock brakes
and there's a problem with your regular brakes. See
ªBrake System Warning Lightº earlier in this section.
The anti
- lock brake system warning light should come
on briefly when you turn the ignition key to RUN. If the
light doesn't come on then, have it fixed so it will be
ready to warn you if there is a problem.