light GMC YUKON DENALI 2008 Owner's Manual

The power liftgate may be temporarily disabled under
extreme temperatures, or under low battery conditions.
If this occurs, the liftgate can still be operated
manually.
If you shift the transmission out of PARK (P) while the
power function is in progress, the liftgate power function
will continue to completion. If you shift the transmission
out of PARK (P) and accelerate before the power
liftgate latches closed, the liftgate may reverse to the
open position. Cargo could fall out of the vehicle. Always
make sure the power liftgate is closed and latched
before you drive away.
If you power open the liftgate and the liftgate support
struts have lost pressure, the lights will ash and a
chime will sound. The liftgate will stay open temporarily,
then slowly close. See your dealer/retailer for service
before using the liftgate.Obstacle Detection Features
If the liftgate encounters an obstacle during a power
open or close cycle, a warning chime will sound and the
liftgate will automatically reverse direction to the full
closed or open position. After removing the obstruction,
the power liftgate operation can be used again. If the
liftgate encounters multiple obstacles on the same power
cycle, the power function will deactivate, and you
must manually open or close the liftgate. The REAR
ACCESS OPEN warning message in the Driver
Information Center (DIC) will indicate that the liftgate is
open. After removing the obstructions, manually
open the liftgate to the full open position or close the
liftgate to the fully closed and latched position. The
liftgate will now resume normal power operation.
Your vehicle has pinch sensors located on the side
edges of the liftgate. If an object is caught between the
liftgate and the body and presses against this sensor,
the liftgate will reverse direction and open fully.
The liftgate will remain open until it is activated again or
closed manually. Do not force the liftgate open or
closed during a power cycle.
2-17

Manual Operation of Power Liftgate
To change the liftgate to manual operation, press the
switch on the center console to the OFF position.
With the power liftgate disabled and all of the doors
unlocked, the liftgate can be manually opened and
closed.
To open the liftgate, press the touchpad on the handle
on the outside of the liftgate, and lift the gate open.
To close the liftgate, use the pull cup to lower the liftgate
and close. The liftgate latch will power close. Always
close the liftgate before driving.
If the RKE button or the power close button on the liftgate
is pressed while power operation is disabled, the lights
will ash three times, but the liftgate will not move.
It is not recommended that you drive with the liftgate
open, however, if you must drive with the liftgate open,
the liftgate should be set to manual operation by
pressing the OFF switch on the center console.
The liftgate has an electric latch. If the battery is
disconnected or has low voltage, the liftgate will not
open. The liftgate will resume operation when the battery
is reconnected and charged.
If the battery is properly connected with adequate
voltage, the switch is not disabled, and the liftgate still
will not function, your vehicle should be taken to a
dealer/retailer for service.
Power Running Boards
Your vehicle may have power running boards.
The power running boards automatically extend from
beneath the vehicle on the side in which the door
has been opened. Once the door is closed, the running
boards will automatically move back under the vehicle
after a brief delay. The vehicle must not be moving
for the running boards to extend or retract.
The switch used to disable
the power running boards
is located on the center
console below the climate
control system.
The running boards cannot be disabled in the extended
position.
2-18

Express-Down Windows
Windows with an express-down feature allow the
windows to be lowered without holding the switch. Press
down fully on the window switch, then release, to
activate the express-down mode. The express-down
mode can be canceled at any time by pulling up on the
front edge of the switch.
Window Lockout
o
(Window Lockout):The window lockout switch is
located with the power window switches on the
driver’s door armrest. This feature prevents the rear
passenger windows from operating, except from
the driver’s position. Press the switch to turn the lockout
feature on or off. An indicator light will come on to
show the lockout feature is on.
Sun Visors
Pull the sun visor down to block glare. Detach the sun
visor from the center mount and slide it along the
rod from side-to-side to cover the driver or passenger
side of the front window. Swing the sun visor to the side
to cover the side window. It can be moved along the
rod from side-to-side in this position also.
Lighted Visor Vanity Mirror
Your vehicle has lighted visor vanity mirrors on both the
driver’s and passenger’s sun visors. Pull the sun
visor down and lift the mirror cover to turn the lamps on.
Theft-Deterrent Systems
Vehicle theft is big business, especially in some cities.
Although your vehicle has a number of theft-deterrent
features, we know that nothing we put on it can make it
impossible to steal.
2-21

Content Theft-Deterrent
Your vehicle has a content theft-deterrent alarm system.
This is the security light.
To arm the theft-deterrent system:
1. Open the door.
2. Lock the door with the Remote Keyless Entry (RKE)
transmitter or the power door lock switch. The
security light will come on to inform the driver the
system is arming. If a door is open when the doors
are locked, the security light will ash.
If the delayed locking feature is turned on, the
theft-deterrent system will not start the arming
process until the last door is closed and the delay
timer has expired. SeeDelayed Locking on
page 2-11.
3. Close all doors. The security light should go off
after about 30 seconds. The alarm is not armed
until the security light goes off.If a locked door is opened without using the RKE
transmitter, a ten second pre-alarm will occur. The horn
will chirp and the lights will ash. If the key is not
placed in the ignition and turned to START or the door
is not unlocked by pressing the unlock button on the
RKE transmitter during the ten second pre-alarm,
the alarm will go off. Your vehicle’s headlamps will ash
and the horn will sound for about two minutes, then
will turn off to save the battery power.
The theft-deterrent system will not activate if the doors
are locked with the vehicle’s key or the manual door lock.
It activates only if you use the power door lock switch with
the door open or the RKE transmitter. You should also
remember that you can start your vehicle with the correct
ignition key if the alarm has been set off.
To avoid setting off the alarm by accident:
If you do not want to activate the theft-deterrent
system, the vehicle should be locked with the
door key after the doors are closed.
Always unlock the doors with the RKE transmitter.
Unlocking a door any other way will set off the
alarm if it is armed.
If you set off the alarm by accident, press unlock on the
RKE transmitter or place the key in the ignition and
turn it to START to turn off the alarm. The alarm will not
stop if you try to unlock a door any other way.
2-22

Testing the Alarm
To test the alarm:
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 RKE transmitter.
3. Get out of the vehicle, close the door and wait for
the security light 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.
While the alarm is set, the power door unlock switch will
not work.
If the alarm does not sound when it should but the
headlamps ash, check to see if the horn works. The
horn fuse may be blown. To replace the fuse, seeFuses
and Circuit Breakers on page 5-108.
If the alarm does not sound or the headlamps do not
ash, the vehicle should be serviced by your
dealer/retailer.
PASS-Key®III+
The PASS-Key®III+ system operates on a radio
frequency subject to Federal Communications
Commission (FCC) Rules and with Industry Canada.
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
1. This device may not cause harmful interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation.
This device complies with RSS-210 of Industry Canada.
Operation is subject to the following two conditions:
1. This device may not cause interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
Changes or modications to this system by other than
an authorized service facility could void authorization to
use this equipment.
PASS-Key
®III+ uses a radio frequency transponder in
the key that matches a decoder in your vehicle.
2-23

PASS-Key®III+ Operation
Your vehicle has PASS-Key®III+ (Personalized
Automotive Security System) theft-deterrent system.
PASS-Key
®III+ is a passive theft-deterrent system.
The system is automatically armed when the key
is removed from the ignition.
The system is automatically disarmed when the key is
turned to ON/RUN, ACC/ACCESSORY or START
from the LOCK/OFF position.
You do not have to manually arm or disarm the system.
The security light will come on if there is a problem
with arming or disarming the theft-deterrent system.
When the PASS-Key
®III+ system senses that someone
is using the wrong key, it prevents the vehicle from
starting. Anyone using a trial-and-error method to start
the vehicle will be discouraged because of the high
number of electrical key codes.
If the engine does not start and the security light on the
instrument panel cluster comes on when trying to
start the vehicle, there may be a problem with your
theft-deterrent system. Turn the ignition off and try again.If the engine still does not start, and the key appears to
be undamaged, try another ignition key. At this time,
you may also want to check the fuse, seeFuses
and Circuit Breakers on page 5-108. If the engine still
does not start with the other key, your vehicle needs
service. If your vehicle does start, the rst key may be
faulty. See your dealer/retailer who can service the
PASS-Key
®III+ to have a new key made. In an
emergency, contact Roadside Assistance.
It is possible for the PASS-Key
®III+ decoder to learn
the transponder value of a new or replacement key. Up
to 10 keys may be programmed for the vehicle. The
following procedure is for programming additional keys
only. If all the currently programmed keys are lost or
do not operate, you must see your dealer/retailer
or a locksmith who can service PASS-Key
®III+ to have
keys made and programmed to the system.
See your dealer/retailer or a locksmith who can service
PASS-Key
®III+ to get a new key blank that is cut
exactly as the ignition key that operates the system.
2-24

To program the new additional key:
1. Verify that the new key has a
1stamped on it.
2. Insert the original, already programmed, key in the
ignition and start the engine. If the engine will not
start, see your dealer/retailer for service.
3. After the engine has started, turn the key to
LOCK/OFF, and remove the key.
4. Insert the new key to be programmed and turn it to
the ON/RUN position within ve seconds of turning
the ignition to the LOCK/OFF position in Step 3.
The security light will turn off once the key has been
programmed.
5. Repeat Steps 1 through 4 if additional keys are to
be programmed.
If you lose or damage your PASS-Key
®III+ key, see
your dealer/retailer or a locksmith who can service
PASS-Key
®III+ to have a new key made.
Do not leave the key or device that disarms or
deactivates the theft deterrent system in the vehicle.
Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:Your vehicle does not need an elaborate
break-in. But it will perform better in the long run if
you follow these guidelines:
Keep your speed at 55 mph (88 km/h) or less for
the rst 500 miles (805 km).
Do not drive at any one constant speed, fast or
slow, for the rst 500 miles (805 km). Do not
make full-throttle starts. Avoid downshifting to
brake or slow the vehicle.
Avoid making hard stops for the rst 200 miles
(322 km) or so. During this time the new brake
linings are not yet broken in. Hard stops
with new linings can mean premature wear and
earlier replacement. Follow this breaking-in
guideline every time you get new brake linings.
Do not tow a trailer during break-in. SeeTowing
a Trailer on page 4-42for the trailer towing
capabilities of your vehicle and more
information.
Following break-in, engine speed and load can be
gradually increased.
2-25

Tow/Haul Mode
Your vehicle has a tow/haul mode. The tow/haul mode
adjusts the transmission shift pattern to reduce shift
cycling, providing increased performance, vehicle
control, and transmission cooling when towing or hauling
heavy loads.Press the button located on the end of the shift lever to
turn the tow/haul on or off. When the tow/haul is on,
a light on the instrument panel cluster will come on.
SeeTow/Haul Mode Light on page 3-47for more
information.
Also see “Tow Haul Mode” underTowing a Trailer on
page 4-42for more information.
The tow/haul mode works with the Autoride
®feature, if
the vehicle has this, to enhance the ride when trailering or
with a loaded vehicle. SeeAutoride
®on page 4-41.
Grade Braking
Grade Braking assists when driving on a downhill grade.
It maintains the vehicle’s speed by automatically
implementing a shift schedule that uses the engine and
the transmission to slow the vehicle. This reduces
wear on the brakes system and increases control of the
vehicle. The system constantly monitors the vehicle’s
speed, acceleration, throttle position, and whether
the brake pedal is being pressed, and determines when
to keep the current vehicle speed or to slow down.
The system will then automatically command downshifts
that reduces the vehicles speed, until the brake pedal
is no longer being pressed. This indicates the desired
vehicle speed has been reached.
2-34

The tow/haul mode and grade braking shift modes can be
activated by pressing the button on the end of the shift
control stalk. While in the DSC mode, grade braking is
deactivated, allowing the driver to select a gear.
SeeAutomatic Transmission Operation on page 2-30for
more information.
Parking Brake
To set the parking brake, hold the regular brake pedal
down with your right foot. Push down the parking
brake pedal with your left foot.
A chime sounds and the warning light ashes when the
parking brake is applied and the vehicle is moving at
least 5 mph (8 km/h).
To release the parking brake, hold the regular brake
pedal down. Then pull the bottom edge of the lever, with
the parking brake symbol and located above the
parking brake pedal.
If the ignition is on when the parking brake is released,
the brake system warning light goes off.
Notice:Driving with the parking brake on can
overheat the brake system and cause premature
wear or damage to brake system parts. Make sure
that the parking brake is fully released and the brake
warning light is off before driving.
If you are towing a trailer and are parking on any hill,
seeTowing a Trailer on page 4-42.
2-35

Mirrors
Automatic Dimming Rearview Mirror
with OnStar
®, Compass and
Temperature Display
When on, an automatic dimming mirror automatically
dims to the proper level to minimize glare from
lights behind you after dark.
The mirror also includes a dual display in the upper
right corner of the mirror face. The compass reading and
the outside temperature will both appear in the display
at the same time.
P(On/Off):This is the on/off button.
Temperature and Compass Display
Press the on/off button, located to the far left, briey to
turn the compass/temperature display on or off.
If the display reads CAL, you will need to calibrate the
compass. For more information on calibration, see
below.To adjust between Fahrenheit and Celsius do the
following:
1. Press and hold the on/off button for approximately
four seconds until either a ashing F or C appears.
2. Press the button again to change the display to the
desired unit of measurement. After approximately
four seconds of inactivity, the new unit will be locked
in and the compass/temperature display will return.
If an abnormal temperature reading is displayed for an
extended period of time, please consult your dealer.
Under certain circumstances, a delay in updating
the temperature is normal.
Automatic Dimming Mirror Operation
The automatic dimming mirror function is turned on
automatically each time the ignition is started. To
operate the automatic dimming mirror, do the following:
1. Make sure the green indicator light, located to the left
of the on/off button, is lit. If it’s not, press and hold the
on/off button for approximately six seconds until the
green light comes on, indicating that the mirror is in
automatic dimming mode.
2. Turn off the automatic dimming mirror function by
pressing and holding the on/off button for
approximately six seconds, until the green indicator
light turns off.
2-40