2008 GMC YUKON Owner's Manual

Engine Exhaust
{CAUTION:
Engine exhaust can kill. It contains the gas
carbon monoxide (CO), which you cannot see or
smell. It can cause unconsciousness and death.
You might have exhaust coming in if:
The exhaust system sounds strange or
different.
Your vehicle gets rusty underneath.
Your vehicle was damaged in a collision.
Your vehicle was damaged when driving
over high points on the road or over road
debris.
CAUTION: (Continued)
CAUTION: (Continued)

Repairs were not done correctly.
Your vehicle or the exhaust system has
been modied improperly.
If you ever suspect exhaust is coming into
your vehicle:
Drive it only with all the windows down to
blow out any CO; and
Have your vehicle xed immediately.
2-47

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 2-47.
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 4-30.
{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).
2-48

{CAUTION:
Four-wheel drive vehicles with the transfer
case in NEUTRAL will allow the vehicle to roll,
even if the shift lever is in PARK (P). So, be
sure the transfer case is in a drive gear — not
in NEUTRAL. Always set the parking brake.
Follow the proper steps to be sure your vehicle will not
move. SeeShifting Into PARK (P) on page 2-44.
If you are pulling a trailer, seeTowing a Trailer on
page 4-49.
Mirrors
Automatic Dimming Rearview Mirror
with OnStar
®, Compass and
Temperature Display
Your vehicle may have this feature. When on, the
automatic dimming mirror dims to the proper level to
minimize glare from lights behind you after dark.
The mirror has a dual display in the upper right corner
of the mirror face that shows the compass reading
and the outside temperature.
Control buttons for the OnStar
®system are at the
bottom of the mirror. SeeOnStar®System on page 2-60
for more information about the services OnStar®
provides.
P(On/Off):This is the on/off button.
2-49

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, the compass needs to be
calibrated. For more information, see “Compass
Calibration” following.
To adjust between Fahrenheit and Celsius:
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, see your dealer/retailer.
Under certain circumstances, a delay in updating the
temperature is normal.
Automatic Dimming Mirror Operation
The automatic dimming mirror comes on each time the
ignition is turned to start. To turn the automatic
dimming feature off or back on, press the on/off button.
The indicator light on the mirror is lit when the
automatic dimming feature is on.
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.
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 the vehicle is
outside of zone eight. Under certain circumstances, as
during a long distance cross-country trip, it will be
necessary to adjust for compass variance.
2-50

Compass variance is the difference between earth’s
magnetic north and true geographic north. If not
adjusted to account for compass variance, the compass
could give false readings.
To adjust for compass variance:
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 appears 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.
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.
2-51

Automatic Dimming Rearview Mirror
with Compass and Temperature
Display
Your vehicle may have this mirror. When on, an
automatic dimming mirror will dim 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 with the compass reading and
the outside temperature.
Yb:Briey press this button to turn the display
on or off.
Temperature Display
The temperature can be displayed by pressing the
compass/temperature button. Pressing the
compass/temperature button once briey, will toggle the
display reading on and off. To alternate the temperature
reading between Fahrenheit and Celsius, press and
hold the compass/temperature button for approximately
three seconds until the display blinks F and C. After
approximately ve seconds of inactivity, the display will
stop blinking and display the last selection made.
If an abnormal reading is displayed, see your
dealer/retailer.
Automatic Dimming Mirror Operation
O
:Press this button to turn the automatic dimming
feature on or off. The indicator light to the left of
the button will turn on to indicate when the feature is on.
Once the mirror is turned off, it will remain off until it
is turned back on, or until the vehicle is restarted.
Compass Operation
Press the compass/temperature button once briey to
turn the display on or off.
Compass Calibration
The compass may need calibration if one of the
following occurs:
If CAL is displayed while driving in the vehicle.
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.
2-52

In order to calibrate, CAL must be displayed in the
mirror compass windows. If CAL is not displayed, push
in the compass/temperature button for approximately
nine 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.
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 the vehicle is
outside 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:
1. Find your current location and variance zone
number on the following zone map.
2. Press and hold the compass/temperature button for
six seconds until a zone number appears in the
display.
3. Press the compass/temperature button on the
bottom of the mirror until the new zone number
appears in the display. After you stop pressing the
button, the display will show a compass direction
within a few seconds.
2-53

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 Manual Mirrors
Adjust your outside mirrors so you can just see the side of
your vehicle and have a clear view of objects behind you.
The mirrors can be folded in to enter narrow areas.
The use of hood-mounted air deectors and add-on
convex mirror attachments may adversely affect mirror
performance.
Outside Trailer-Tow Mirrors
If your vehicle has trailer towing type mirrors, they can
be adjusted so you can have a clear view of the
objects behind you. Manually pull out the mirror head to
extend it for better visibility when towing a trailer.
These mirrors can be manually folded forward or
rearward. The lower portion of the mirror is convex.
A convex mirror’s surface is curved so you can see more
from the driver’s seat. The convex mirror can be
adjusted manually to the driver’s preferred position for
better vision.
2-54