2008 GMC ENVOY Owner's Manual

{CAUTION:
If your vehicle has four-wheel drive, it will
be free to roll — even if the shift lever is in
PARK (P) — if the transfer case is in
NEUTRAL. So be sure the transfer case
is in a drive gear — not in NEUTRAL.
SeeFour-Wheel Drive on page 2-29.
Follow the proper steps to be sure your vehicle will not
move. SeeShifting Into PARK (P) on page 2-34.
If you are pulling a trailer, seeTowing a Trailer on
page 4-45.
Mirrors
Manual Rearview Mirror
When you are sitting in a comfortable driving position,
adjust the mirror so you can see clearly behind your
vehicle. Grip the mirror in the center to move it up
or down and side to side. The day/night adjustment
allows you to adjust the mirror to avoid glare from the
lamps behind you. Move the lever to the right for
nighttime use and to the left for daytime use.
Manual Rearview Mirror with
OnStar
®
When you are sitting in a comfortable driving position,
adjust the mirror so you can see clearly behind your
vehicle. Hold the mirror in the center to move it up or
down and side to side. The day/night adjustment allows
you to adjust the mirror to avoid glare from the lamps
behind you. Move the lever to the right for nighttime
use and to the left for daytime use.
There may also be three OnStar
®buttons located at the
bottom of the mirror face. See your dealer/retailer for
more information on the system and how to subscribe to
OnStar
®. SeeOnStar®System on page 2-48for more
information on the services OnStar®provides.
Automatic Dimming Rearview Mirror
with OnStar
®and Compass
Your vehicle may have an automatic-dimming rearview
mirror with a compass.
There may be three additional buttons for the OnStar
®
system. See your dealer/retailer for more information
on the system and how to subscribe to OnStar®.
SeeOnStar®System on page 2-48for more information
about the services OnStar®provides.
O(On/Off):This is the on/off button.
2-39

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 Operation
Press the on/off button once to turn the compass
on or off.
There is a compass display in the window in the upper
right corner of the mirror face.
Compass Calibration
Press and hold the on/off button to activate the compass
calibration mode. CAL will be displayed in the compass
window on the mirror.
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.If after a few seconds the display does not show a
compass direction, (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, note pad holder, or similar object. If the letter C or
CAL appears in the compass window, the compass may
need to be reset or calibrated.
Compass Variance
Compass variance is the difference between earth’s
magnetic north and true geographic north. The mirror
is set to zone eight upon leaving the factory. It will be
necessary to adjust the compass to compensate for
compass variance if you live outside zone eight. Under
certain circumstances, such as during a long distance
cross-country trip, it will be necessary to adjust for
compass variance. If not adjusted to account for compass
variance, your compass could give false readings.
2-40

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 the zone
number is displayed. The number shown is the
current zone number.3. Scroll through the zone numbers that appear in the
window on the mirror by pressing the on/off button.
Once you nd your zone number, release the button.
After about four seconds, the mirror will return to the
compass display, and the new zone number will be
set. If C or CAL appears in the compass window,
the compass may need calibration. See “Compass
Calibration” listed previously.
Automatic Dimming Rearview Mirror
with OnStar
®, Compass and
Temperature Display
Your vehicle may have this feature. 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.
2-41

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 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 until the
green indicator light turns off.
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 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 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.
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.
2-42

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 next.
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, press
and hold the on/off button 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.
2-43

Passenger Airbag Indicator
The vehicle may be equipped with a passenger airbag
indicator, on the mirror glass, just above the buttons.
If the vehicle has this feature, the mirror will display the
word ON, or an airbag symbol in Canada, when the
passenger airbag is enabled. For more information,
seePassenger Sensing System on page 1-61.
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.
Automatic Dimming Rearview Mirror
with Compass and Temperature
Display
If the vehicle is equipped with an automatic mirror,
it will, when on, automatically dim to the proper level
to minimize glare from lights behind you after dark.
The mirror also includes a 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. The dual display can be
turned on or off by briey pressing either the TEMP
or the COMP button.
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 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 until the
green indicator light turns off.
Temperature Display
The temperature can be displayed by pressing the
TEMP button. Pressing the TEMP button once briey, will
toggle the temperature reading on and off. To alternate
the temperature reading between Fahrenheit and
Celsius, press and hold the TEMP button until the display
blinks F and C. Press and release the TEMP button to
toggle between the Fahrenheit and Celsius readings.
After approximately four seconds of inactivity, the display
will stop blinking and display the last selection made.
If an abnormal reading is displayed, for an extended
period of time, please consult your dealer. Under certain
circumstances, a delay in updating the temperature is
normal.
2-44

Compass Operation
Press the COMP button once briey to turn the compass
on or off.
When the ignition and the compass feature are on, the
compass will show two character boxes for approximately
two seconds. After two seconds, the mirror will display
the compass heading.
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.In order to calibrate, CAL must be displayed in the
mirror compass windows. If CAL is not displayed, press
and hold the COMP button 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 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.
2-45

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 COMP button until a zone
number appears in the display.
3. Press the COMP 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.Passenger Airbag Indicator
The mirror may be equipped with a passenger airbag
indicator on the mirror glass, just above the buttons.
If the vehicle has this feature the mirror will display the
word ON, or an airbag symbol in Canada, when the
passenger airbag is enabled. For more information
seePassenger Sensing System on page 1-61.
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 Manual Mirrors
Adjust the outside rearview mirrors so you can see a
little of the side of your vehicle, and the area beside your
vehicle from a comfortable driving position. The mirrors
can be folded in to enter narrow areas. Return the mirrors
to the unfolded position before driving.
2-46