2009 GMC YUKON service

Four-Wheel Drive
If the vehicle has four-wheel drive, you can send the
engine’s driving power to all four wheels for extra
traction. Read the following before using four-wheel
drive.
Notice:Driving on clean, dry pavement in
Four-Wheel-Drive High or Four-Wheel-Drive Low for
an extended period of time may cause premature
wear on your vehicle’s powertrain. Do not drive on
clean, dry pavement in Four-Wheel-Drive High or
Four-Wheel-Drive Low for extended periods of time.
While driving on clean dry pavement and during tight
turns, you may experience a vibration in the steering
system.
The vehicle has StabiliTrak
®. Shifting into
Four-Wheel-Drive Low will turn Traction Control and
StabiliTrak
®off. SeeStabiliTrak®System on page 4-6.
Front Axle
The front axle engages and disengages automatically
when you shift the transfer case. Some delay for
the axle to engage or disengage is normal.
Automatic Transfer Case
The transfer case knob is
located to the left of the
instrument panel cluster.
Use this dial to shift into and out of four-wheel drive.
You can choose among ve driving settings:
Indicator lights in the switches show you which setting
you are in. The indicator lights will come on briey when
you turn on the ignition and the last chosen setting
will stay on. If the lights do not come on, you should take
the vehicle to your dealer/retailer for service. An
indicator light will ash while shifting. It will stay on
when the shift is completed. If for some reason
the transfer case cannot make a requested shift, it will
return to the last chosen setting.
2-37

2m(Two-Wheel Drive High):This setting is used for
driving in most street and highway situations. The
front axle is not engaged in two-wheel drive. This setting
also provides the best fuel economy.
AUTO (Automatic Four-Wheel Drive):This setting is
ideal for use when road surface traction conditions are
variable. When driving your vehicle in AUTO, the front
axle is engaged, but the vehicle’s power is primarily sent
to the rear wheels. When the vehicle’s software
determines a need for more traction, the system will
transfer more power to the front wheels. Driving in this
mode results in slightly lower fuel economy than
Two-Wheel Drive High.
4
m(Four-Wheel Drive High):Use the four-wheel high
position when you need extra traction, such as on snowy
or icy roads or in most off-road situations. This setting
also engages your front axle to help drive the vehicle.
This is the best setting to use when plowing snow.
4
n(Four-Wheel Drive Low):This setting also engages
the front axle and delivers extra torque. You may never
need this setting. It sends maximum power to all four
wheels. You might choose Four-Wheel Drive Low if you
are driving off-road in deep sand, deep mud, deep snow,
and while climbing or descending steep hills.
The vehicle has StabiliTrak
®. Shifting into
Four-Wheel-Drive Low will turn Traction Control and
StabiliTrak
®off. SeeStabiliTrak®System on page 4-6.
{CAUTION:
Shifting the transfer case to N (Neutral) can cause
the vehicle to roll even if the transmission is in
P (Park). You or someone else could be seriously
injured. Be sure to set the parking brake before
placing the transfer case in N (Neutral). See
Parking Brake on page 2-42.
N (Neutral):Shift the vehicle’s transfer case to
N (Neutral) only when towing the vehicle. See
Recreational Vehicle Towing on page 4-44orTowing
Your Vehicle on page 4-44for more information.
If the SERVICE 4 WHEEL DRIVE message stays on,
you should take the vehicle to your dealer/retailer
for service. See “SERVICE 4 WHEEL DRIVE message”
underDIC Warnings and Messages on page 3-64.
2-38

If you have to leave the vehicle with the engine running,
be sure your vehicle is in P (Park) and the parking brake
is rmly set before you leave it. After you move the shift
lever into P (Park), hold the regular brake pedal down.
Then, see if you can move the shift lever away from
P (Park) without rst pulling it toward you. If you can, it
means that the shift lever was not fully locked into
P (Park).
Torque Lock
If you are parking on a hill and you do not shift your
transmission into P (Park) properly, the weight of the
vehicle may put too much force on the parking pawl in
the transmission. You may nd it difficult to pull the shift
lever out of P (Park). This is called torque lock. To
prevent torque lock, set the parking brake and then shift
into P (Park) properly before you leave the driver seat.
To nd out how, seeShifting Into Park on page 2-44.
When you are ready to drive, move the shift lever out
of P (Park) before you release the parking brake.
If torque lock does occur, you may need to have another
vehicle push yours a little uphill to take some of the
pressure from the parking pawl in the transmission, then
you will be able to pull the shift lever out of P (Park).
Shifting Out of Park
This vehicle is equipped with an electronic shift lock
release system. The shift lock release is designed to:
Prevent ignition key removal unless the shift
lever is in P (Park) with the shift lever button fully
released, and
Prevent movement of the shift lever out of
P (Park), unless the ignition is in ON/RUN or
ACC/ACCESSORY and the regular brake pedal is
applied.
The shift lock release is always functional except in the
case of an uncharged or low voltage (less than 9 volt)
battery.
If the vehicle has an uncharged battery or a battery with
low voltage, try charging or jump starting the battery.
SeeJump Starting on page 5-45for more information.
To shift out of P (Park) use the following:
1. Apply the brake pedal.
2. Move the shift lever to the desired position.
If you still are unable to shift out of P (Park):
1. Ease the pressure on the shift lever.
2. While holding down the brake pedal, press the shift
lever all the way into P (Park).
3. Move the shift lever to the desired position.
If you are still having a problem shifting, then have the
vehicle serviced soon.
2-45

{CAUTION:
It can be dangerous to get out of the vehicle if the
automatic transmission shift lever is not fully in
P (Park) with the parking brake rmly set. The
vehicle can roll. Do not leave the vehicle when the
engine is running unless you have to. If you have
left the engine running, the vehicle can move
suddenly. You or others could be injured. To be
sure the vehicle will not move, even when you are
on fairly level ground, always set the parking
brake and move the shift lever to P (Park).
{CAUTION:
Four-wheel drive vehicles with the transfer case
in N (Neutral) will allow the vehicle to roll, even
if the automatic transmission shift lever is in
P (Park). So, be sure the transfer case is in a
drive gear — not in N (Neutral). Always set the
parking brake.Follow the proper steps to be sure the vehicle will not
move. SeeShifting Into Park on page 2-44.
If pulling a trailer, seeTowing a Trailer on page 4-52.
Mirrors
Manual Rearview Mirror
Hold the inside rearview mirror in the center to move it
for a clearer view behind your vehicle. Adjust the
mirror to avoid glare from the headlamps behind you.
Push the tab forward for daytime use and pull it for
nighttime use.
Automatic Dimming Rearview Mirror
The vehicle may have an automatic dimming rearview
mirror.
Vehicles with OnStar
®have three additional control
buttons for the OnStar®system. See your dealer/retailer
for more information about OnStar®and how to
subscribe to it. SeeOnStar®System on page 2-64for
more information about the services OnStar®provides.
2-48

When the System Does Not Seem To Work
Properly
Occasional missed alerts can occur under normal
circumstances and will increase in wet conditions. The
system does not need to be serviced due to an
occasional missed alert. The number of missed alerts
will increase with increased rainfall or road spray.
If the SBZA displays do not light up when the system is
on and vehicles are in the blind zone, the system may
need service. Take the vehicle to your dealer/retailer.
SBZA is designed to ignore stationary objects; however,
the system may occasionally light up due to guard
rails, signs, trees, shrubs, and other stationary objects.
This is normal system operation, the vehicle does
not need service.SBZA does not operate when the left or right corners of
the rear bumper are covered with mud, dirt, snow,
ice, slush, or in heavy rainstorms. For cleaning
instructions, seeWashing Your Vehicle on page 5-111.
If the DIC still displays the SIDE BLIND ZONE SYS.
UNAVAILABLE message after cleaning the bumper, see
your dealer/retailer.
The SBZA displays may remain on if a trailer is attached
to the vehicle, or a bicycle or object is extending out
to either side of the vehicle.
When SBZA is disabled for any reason other than the
driver turning it off, the driver will not be able to turn SBZA
back on using the DIC. The SIDE BLIND ZONE ALERT
ON option will not be selectable if the conditions for
normal system operation are not met. Until normal
operating conditions for SBZA are met, you should not
rely upon SBZA while driving.
2-58

SBZA Error Messages
The following messages may appear in the DIC:
SIDE BLIND ZONE ALERT SYSTEM OFF:This
message indicates that the driver has turned the
system off.
SIDE BLIND ZONE SYS. UNAVAILABLE:This
message indicates that the SBZA system is disabled
either because the sensor is blocked and cannot detect
vehicles in your blind zone, or the vehicle is passing
through an open eld of view area, such as the desert,
where there is insufficient data for operation. The
sensor may be blocked by mud, dirt, snow, ice, slush,
or even heavy rainstorms. This message may also
activate during heavy rain or due to road spray. The
vehicle does not need service. For cleaning, see
Washing Your Vehicle on page 5-111.
SERVICE SIDE BLIND ZONE ALERT SYSTEM:If this
message appears, both SBZA displays will remain on
indicating there is a problem with the SBZA system.
If these displays remain on after continued driving, the
system needs service. Take the vehicle to your
dealer/retailer.
Rear Vision Camera (RVC)
This vehicle may have a Rear Vision Camera system.
Read this entire section before using it.
{CAUTION:
The Rear Vision Camera (RVC) system does not
replace driver vision. RVC does not:
Detect objects that are outside the camera’s
eld of view, below the bumper, or
underneath the vehicle.
Detect children, pedestrians, bicyclists, or pets.
Do not back the vehicle by only looking at the rear
vision camera screen, or use the screen during
longer, higher speed backing maneuvers or where
there could be cross-traffic. Your judged distances
using the screen will differ from actual distances.
So if you do not use proper care before backing up,
you could hit a vehicle, child, pedestrian, bicyclist,
or pet, resulting in vehicle damage, injury, or death.
Even though the vehicle has the RVC system,
always check carefully before backing up by
checking behind and around the vehicle.
2-59

To turn the symbols on or off:
1. Make sure that URPA has not been disabled.
2. Shift into P (Park).
3. Press the MENU hard key to enter the congure
menu options, then press the MENU hard key
repeatedly until Display is selected or touch
the Display screen button.
4. Select the Rear Camera Options screen button.
The Rear Camera Options screen will display.
5. Touch the Symbols screen button. The screen
button will be highlighted when on.
Rear Vision Camera Error Messages
Service Rear Vision Camera System:This message
can display when the system is not receiving
information it requires from other vehicle systems.
If any other problem occurs or if a problem persists, see
your dealer/retailer.
Rear Vision Camera Location
The image is provided by the camera located above the
license plate.
The camera uses a special lens. The distance of the
image that appears on the screen differs from the actual
distance. The area displayed by the camera is limited.
The camera does not display objects which are close to
either corner of the bumper or under the bumper. The
area displayed on the screen can vary according to
vehicle orientation or road conditions.
2-62

The rear vision camera system display in the rearview
mirror may turn off or not appear as expected due to
one of the following conditions. If this occurs the
left indicator light on the mirror will ash.
A slow ash may indicate a loss of video signal, or
no video signal present during the reverse cycle.
A fast ash may indicate that the display has been
on for the maximum allowable time during a
reverse cycle, or the display has reached an Over
Temperature limit.
The fast ash conditions are used to protect the
video device from high temperature conditions. Once
conditions return to normal the device will reset and
the green indicator will stop ashing.
During any of these fault conditions, the display will be
blank and the indicator will continue to ash as long
as the vehicle is in R (Reverse) or until the conditions
return to normal.
Pressing and holding
zwhen the left indicator light is
ashing will turn off the video display along with the
left indicator light.
OnStar®System
OnStar uses several innovative technologies and live
advisors to provide a wide range of safety, security,
information, and convenience services. If the airbags
deploy, the system is designed to make an automatic
call to OnStar Emergency advisors who can request
emergency services be sent to your location. If the keys
are locked in the vehicle, call OnStar at 1-888-4-ONSTAR
to have a signal sent to unlock the doors. OnStar
Hands-Free Calling, including 30 trial minutes good for
60 days, is available on most vehicles. OnStar
Turn-by-Turn Navigation service, with one trial route, is
available on most vehicles. Press the OnStar button to
have an OnStar advisor contact Roadside Service.
OnStar service is provided subject to the OnStar Terms
and Conditions included in the OnStar Subscriber
glove box literature.
2-64