2007 GMC SIERRA Owner's Manual

{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 163.
If you are pulling a trailer, seeTowing a Trailer
on page 445.
Mirrors
Manual Rearview Mirror
Pull or push the tab under the inside rearview
mirror to adjust it to the night or daytime setting. In
the nighttime setting, the glare from headlamps
behind the vehicle will be less intense.
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 180for more information about the services
OnStar
®provides.
P(On/Off):This is the on/off button.
169

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, 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, see your
dealer. Under certain circumstances, a delay in
updating the temperature is normal.
170

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 is 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.
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.
171

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. 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, 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 untilaZand
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.
172

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
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 temperature reading is displayed
for an extended period of time, see your
dealer. Under certain circumstances, a delay in
updating the temperature is normal.
173

Automatic Dimming Mirror Operation
O
On/Off: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
See “Compass Calibration” underAutomatic
Dimming Rearview Mirror with OnStar®, Compass
and Temperature Display on page 169for more
information.
Compass Variance
See “Compass Variance” underAutomatic
Dimming Rearview Mirror with OnStar®, Compass
and Temperature Display on page 169for more
information.
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.
174

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.
Your vehicle may have outside heated mirrors
which help clear them of condensation, snow, and
ice. When the rear window defogger button is
pressed, the heated mirrors are also turned on.
Only the upper glass of the mirror is heated.
The lower convex part of the mirror is not heated.
Your mirror may also have a turn signal arrow
that will ash in the direction of the turn or
lane change.
175

Outside Power Mirrors
If your vehicle is
equipped with outside
power mirrors, the
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.
This mirror has the following features.
Manual Folding
The mirrors can be manually folded inward to
prevent damage when going through an automatic
car wash. To fold, push the mirror toward the
vehicle. To return the mirror to its original position,
push outward. Be sure to return both mirrors to
their original unfolded position before driving.
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 238
for more information.
176