2008 GMC YUKON DENALI ignition

C (ON/RUN):This is the position for driving. It is the
position the ignition switch returns to after the engine
starts, and the key is released.
The battery could be drained if you leave the key in the
ACC/ACCESSORY or ON/RUN position with the engine
off. You may not be able to start your vehicle if the battery
is allowed to drain for an extended period of time.
D (START):This position starts the engine.
Key In the Ignition
Never leave your vehicle with the keys inside, as it is an
easy target for joy riders or thieves. If you leave the
key in the ignition and park your vehicle, a chime
will sound, when you open the driver’s door. Always
remember to remove your key from the ignition and take
it with you. This will lock your ignition and transmission.
Also, always remember to lock the doors.
The battery could be drained if you leave the key in the
ignition while your vehicle is parked. You may not be
able to start your vehicle after it has been parked for an
extended period of time.
Retained Accessory Power (RAP)
The following vehicle accessories can be used for up to
10 minutes after the engine is turned off:
Audio System
Power Windows
OnStar®System (if equipped)
Sunroof (if equipped)
These features work when the key is in ON/RUN or
ACC/ACCESSORY. Once the key is turned from
ON/RUN to LOCK/OFF, the windows and sunroof
continue to work up to 10 minutes until any door
is opened. The radio continues to work for up to
10 minutes or until the driver’s door is opened.
Starting the Engine
Move your shift lever to PARK (P) or NEUTRAL (N).
Your engine will not start in any other position – this is a
safety feature. To restart when you are already
moving, use NEUTRAL (N) only.
Notice:Do not try to shift to PARK (P) if your
vehicle is moving. If you do, you could damage the
transmission. Shift to PARK (P) only when your
vehicle is stopped.
2-27

Starting Procedure
1. With your foot off the accelerator pedal, turn the
ignition key to START. When the engine starts,
let go of the key. The idle speed will go down as
your engine gets warm. Do not race the engine
immediately after starting it. Operate the engine and
transmission gently to allow the oil to warm up
and lubricate all moving parts.
Your vehicle has a Computer-Controlled Cranking
System. This feature assists in starting the
engine and protects components. If the ignition key
is turned to the START position, and then
released when the engine begins cranking, the
engine will continue cranking for a few seconds or
until the vehicle starts. If the engine does not
start and the key is held in START for many
seconds, cranking will be stopped after 15 seconds
to prevent cranking motor damage. To prevent
gear damage, this system also prevents cranking if
the engine is already running. Engine cranking
can be stopped by turning the ignition switch to the
ACC/ACCESSORY or LOCK/OFF position.
Notice:Cranking the engine for long periods of
time, by returning the key to the START position
immediately after cranking has ended, can overheat
and damage the cranking motor, and drain the
battery. Wait at least 15 seconds between each try,
to let the cranking motor cool down.2. If the engine does not start after 5-10 seconds,
especially in very cold weather (below 0°F or−18°C),
it could be ooded with too much gasoline. Try
pushing the accelerator pedal all the way to the oor
and holding it there as you hold the key in START for
up to a maximum of 15 seconds. Wait at least
15 seconds between each try, to allow the cranking
motor to cool down. When the engine starts, let go of
the key and accelerator. If the vehicle starts briey
but then stops again, do the same thing. This clears
the extra gasoline from the engine. Do not race the
engine immediately after starting it. Operate the
engine and transmission gently until the oil warms up
and lubricates all moving parts.
Notice:The engine is designed to work with the
electronics in your vehicle. If you add electrical
parts or accessories, you could change the way the
engine operates. Before adding electrical equipment,
check with your dealer/retailer. If you do not, your
engine might not perform properly. Any resulting
damage would not be covered by your vehicle’s
warranty.
2-28

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

Shifting Into PARK (P)
{CAUTION:
It can be dangerous to get out of your vehicle
if the shift lever is not fully in PARK (P) with
the parking brake rmly set. Your vehicle can
roll. If you have left the engine running, the
vehicle can move suddenly. You or others
could be injured. To be sure your vehicle will
not move, even when you are on fairly level
ground, use the steps that follow. If you are
pulling a trailer, seeTowing a Trailer on
page 4-42.
1. Hold the brake pedal down with your right foot and
set the parking brake.
2. Move the shift lever into the PARK (P) position by
pulling the shift lever toward you and moving it up
as far as it will go.
3. Turn the ignition key to LOCK/OFF.
4. Remove the key and take it with you. If you can
leave your vehicle with the ignition key in your
hand, your vehicle is in PARK (P).
Leaving Your Vehicle With the Engine
Running
{CAUTION:
It can be dangerous to leave your vehicle with
the engine running. Your vehicle could move
suddenly if the shift lever is not fully in
PARK (P) with the parking brake rmly set.
And, if you leave the vehicle with the engine
running, it could overheat and even catch re.
You or others could be injured. Do not leave
your vehicle with the engine running.
If you have to leave your vehicle with the engine
running, be sure your vehicle is in PARK (P) and the
parking brake is rmly set. After the shift lever is moved
into PARK (P), hold the regular brake pedal down.
Then, see if you can move the shift lever away from
PARK (P) without rst pulling it toward you. If you can, it
means that the shift lever was not fully locked into
PARK (P).
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Torque Lock
If you are parking on a hill and you do not shift your
transmission into PARK (P) properly, the weight of the
vehicle can put too much force on the parking pawl in the
transmission. It might be difficult to pull the shift lever out
of PARK (P). This is called torque lock. To prevent torque
lock, set the parking brake and then shift into PARK (P)
properly before you leave the driver’s seat. To nd out
how, seeShifting Into PARK (P) on page 2-36.
When you are ready to drive, move the shift lever out of
PARK (P) before releasing the parking brake.
If torque lock does occur, you might 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 should be able to pull the shift lever out of PARK (P).
Shifting Out of PARK (P)
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 PARK (P) with the shift lever button fully
released, and
Prevent movement of the shift lever out of
PARK (P), 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 your vehicle has an uncharged battery or a battery
with low voltage, try charging or jump starting the
battery. SeeJump Starting on page 5-40for more
information.
To shift out of PARK (P) 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 PARK (P):
1. Ease the pressure on the shift lever.
2. While holding down the brake pedal, press the shift
lever all the way into PARK (P).
3. Move the shift lever to the desired position.
If you are still having a problem shifting, then have your
vehicle serviced soon.
2-37

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

If the mirrors are accidentally folded/unfolded manually,
they may shake or utter at normal driving speeds
and may not stay in the unfolded position. If this
happens, you will need to reset the mirrors. See
“Resetting the Power Foldaway Mirrors” next.
Resetting the Power Foldaway Mirrors
You will need to reset the power foldaway mirrors if the
following occurs:
The mirrors are accidentally obstructed while
folding.
They are accidentally manually folded/unfolded.
The mirrors will not stay in the unfolded position.
The mirrors shake and utter at normal driving
speeds.
To reset the power foldaway mirrors, fold and unfold
them one time using the mirror controls. This will reset
them to their normal position.
This mirror has the following features.
Automatic Dimming
The driver’s outside mirror will adjust for the glare of the
headlamps behind you. SeeAutomatic Dimming
Rearview Mirror with OnStar
®, Compass and
Temperature Display on page 2-40.
Curb View Assist
If your vehicle has the memory package, the outside
mirrors are able to perform the park tilt function. This
feature may be useful in allowing the driver to view the
curb when parallel parking. This feature will cause the
passenger’s and/or driver’s mirror to tilt to a preselected
position when the vehicle is in REVERSE (R).
The passenger’s and/or driver’s mirror will return to its
original position when the vehicle is shifted out of
REVERSE (R), or the ignition is turned off or to
OFF/LOCK.
This feature can be turned on or off through the Driver
Information Center (DIC). SeeDIC Vehicle
Customization (With DIC Buttons) on page 3-64.
Heated Mirrors
The button to turn the heated mirrors on or off is located
on the climate control panel. Press this button to
warm the driver’s and passenger’s outside rearview
mirrors to help clear them of ice, snow, and
condensation.
See “Rear Window Defogger” underDual Automatic
Climate Control System on page 3-23for more
information.
2-43

Cargo Tie Downs
Your vehicle may have cargo tie downs in the rear
cargo area that allow you to strap cargo in and keep it
from moving inside the vehicle.
Sunroof
Your vehicle may be equipped with a power sliding
sunroof. To open or close the sunroof, the ignition needs
to be turned to ON, or Retained Accessory Power
(RAP) must be active. When RAP is active, the sunroof
will work for 10 minutes after the ignition is turned
off, or until a front door is opened. SeeRetained
Accessory Power (RAP) on page 2-27for more
information.
There are two switches in
the overhead console that
operate the sunroof.Manual-Open/Manual-Close:To open the sunroof
press and hold the rear of the driver’s side switch until
the sunroof reaches the desired position. To close
the sunroof, press and hold the front of the driver’s side
switch until the sunroof reaches the desired position.
The sunshade will open automatically with the sunroof,
but can also be opened manually.
The sunroof has a comfort stop feature which stops the
sunroof from opening to the full-open position. From
the comfort stop position, press the rear of the driver’s
side switch a second time to open the sunroof to
the full-open position.
When the sunroof is opened, an air deector will
automatically raise. The air deector will retract when
the sunroof is closed.
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