2008 GMC YUKON DENALI Owners Manual

Running the Engine While Parked
It is better not to park with the engine running. But if you
ever have to, here are some things to know.
{CAUTION:
Idling the engine with the climate control
system off could allow dangerous exhaust into
your vehicle. See the earlier caution under
Engine Exhaust on page 2-38.
Also, idling in a closed-in place can let deadly
carbon monoxide (CO) into your vehicle even if
the climate control fan is at the highest setting.
One place this can happen is a garage.
Exhaust — with CO — can come in easily.
NEVER park in a garage with the engine
running.
Another closed-in place can be a blizzard. See
Winter Driving on page 4-29.
{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. Do not leave your 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 your vehicle will not move, even when
you are on fairly level ground, always set the
parking brake and move the shift lever to
PARK (P).
Follow the proper steps to be sure your vehicle will not
move. SeeShifting Into PARK (P) on page 2-36.
If you are pulling a trailer, seeTowing a Trailer on
page 4-42.
2-39

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

Compass Variance
The mirror is set in zone eight upon leaving the factory.
It will be necessary to adjust the compass to
compensate for compass variance if you live outside of
zone eight. Under certain circumstances, as during a
long distance cross-country trip, it will be necessary to
adjust for compass variance. Compass variance is
the difference between earth’s magnetic north and true
geographic north. If not adjusted to account for
compass variance, your compass could give false
readings.
To adjust for compass variance do the following:
1. Find your current location and variance zone
number on the following zone map.
2. Press and hold the on/off button until a Z and a
zone number appear in the display. The compass
is now in zone mode.
3. Keep pressing the on/off button until the desired
zone number appears in the display. Release the
button. After approximately four seconds of
inactivity, the new zone number will be locked in
and the compass/temperature display will return.
4. Calibrate the compass as described below.
2-41

Compass Calibration
The compass may need calibration if one of the
following occurs:
After approximately ve seconds, the display does
not show a compass heading (N for North, for
example), there may be a strong magnetic eld
interfering with the compass. Such interference may
be caused by a magnetic antenna mount, magnetic
note pad holder or a similar magnetic item.
The compass does not display the correct heading
and the compass zone variance is set correctly.
In order to calibrate, CAL must be displayed in the
mirror compass windows. If CAL is not displayed, push
the on/off button for approximately 12 seconds or
until CAL is displayed.
The compass can be calibrated by driving the vehicle in
circles at 5 mph (8 km/h) or less until the display
reads a direction.
Cleaning the Mirror
When cleaning the mirror, use a paper towel or similar
material dampened with glass cleaner. Do not spray
glass cleaner directly on the mirror as that may cause
the liquid cleaner to enter the mirror housing.
Outside Power Foldaway Mirrors
The outside power
foldaway mirror controls
are located on the driver’s
door armrest.
Press (A) to select the driver’s side mirror. Then
press the arrows located on the four-way control
pad to adjust the mirror. Press (A) again to deselect
the mirror.
Press (B) to select the passenger’s side mirror.
Then press the arrows located on the four-way
control pad to adjust the mirror. Press (B) again to
deselect the mirror.
Press (C) to fold the mirrors out to the driving
position.
Press (D) to fold the mirrors in to the folded position.
2-42

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

Convex Mirror
{CAUTION:
A convex mirror can make things (like other
vehicles) look farther away than they really are.
If you cut too sharply into the right lane, you
could hit a vehicle on your right. Check your
inside mirror or glance over your shoulder
before changing lanes.
The passenger’s side mirror may have convex glass.
A convex mirror’s surface is curved so more can
be seen from the driver’s seat.
Your vehicle has a turn signal indicator on the mirror.
An arrow on the mirror will ash in the direction of
the turn or lane change.
Object Detection Systems
Ultrasonic Rear Parking
Assist (URPA)
If your vehicle has the Ultrasonic Rear Parking Assist
(URPA) system, it helps you park easier and avoid other
vehicles while in REVERSE (R). It operates at speeds
less than 5 mph (8 km/h). It can determine how close
objects are to the rear bumper, up to 8 feet (2.5 m)
behind your vehicle. The distance sensors are located
on the rear bumper.
2-44

{CAUTION:
The Ultrasonic Rear Parking Assist (URPA)
system does not replace driver vision.
It cannot detect:
objects that are below the bumper,
underneath the vehicle, or if they are
too close or far from the vehicle
children, pedestrians, bicyclists, or pets.
If you do not use proper care before and while
backing; vehicle damage, injury, or death
could occur. Even with URPA, always check
behind your vehicle before backing up. While
backing, be sure to look for objects and check
your vehicle’s mirrors.On some vehicles this
display is located near the
passenger side rear
window and can be seen
by looking over your
right shoulder.
If your vehicle has the display, there are three
color-coded lights to provide distance and system
information.
If your vehicle does not have the display and it has
URPA, you will hear the beeps as described in the
following information.
How the System Works
URPA comes on automatically when the shift lever is
moved into REVERSE (R). The rear display will
then briey illuminate to let you know the system is
working.
URPA operates only at speeds less than 5 mph (8 km/h).
If you are above this speed, the red light on the rear
display will ash.
2-45

To be detected, objects must be at least 10 inches
(25.4 cm) off the ground and below liftgate level. Objects
must also be within 8 feet (2.5 m) from your rear
bumper. This distance may be less during warmer or
humid weather.
A single beep will sound the rst time an object is
detected between 20 inches (0.5 m) and 8 feet (2.5 m)
away. Beeping will occur for three seconds when
you are closer than 1 foot (0.3 m) from the object.
The following describes what will occur with the URPA
display as you get closer to a detected object:
Description English Metric
amber light 8 ft 2.5 m
amber/amber lights 40 in 1.0 m
amber/amber/red lights 23 in 0.6 m
amber/amber/red lights
ashing and beep for
three seconds1 ft 0.3 mThe system can be
disabled by pressing the
rear park aid disable button
located next to the radio.
The indicator light will
come on to indicate that
URPA is off.
When the System Does Not Seem to
Work Properly
The driver disables the system.
The parking brake pedal is depressed.
The ultrasonic sensors are not clean. Keep your
vehicle’s rear bumper free of mud, dirt, snow,
ice and slush. For cleaning instructions, see
Washing Your Vehicle on page 5-102.
A trailer was attached to your vehicle, or a bicycle
or an object was hanging out of your liftgate/liftglass
during your last drive cycle, the red light may
illuminate in the rear display. Once the attached
object is removed, URPA will return to normal
operation.
2-46