GMC SIERRA CLASSIC 2007 Owners Manual

Leaving Your Vehicle With the Engine
Running (Automatic Transmission)
{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.
If you have four-wheel drive and your
transfer case is in NEUTRAL, your vehicle
will be free to roll, even if your shift lever
is in PARK (P). So be sure the transfer
case is in a drive gear — not in NEUTRAL.
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 unless you have to.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 before
you leave it. After you move the shift lever 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).
Torque Lock (Automatic Transmission)
If you are parking on a hill and you do not shift
your transmission into PARK (P) properly,
the weight of the vehicle may put too much force
on the parking pawl in the transmission. You
may nd it 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, see “Shifting Into
PARK (P)” listed earlier in this section.
When you are ready to drive, move the shift lever
out of PARK (P) before you release the parking
brake.
171

If torque lock does occur, you may need to have
another vehicle push yours a little uphill to
take some of the pressure from the parking pawl
in the transmission, so you can pull the shift
lever out of PARK (P).
Shifting Out of Park (P)
(Automatic Transmission)
Your vehicle has an automatic transmission shift
lock control system which locks the shift lever
in PARK (P) when the ignition is in the LOCK
position. You have to fully apply your regular
brakes before you can shift from PARK (P) when
the ignition is in RUN. SeeAutomatic Transmission
Operation on page 140and “Torque Lock”
underShifting Out of Park (P) (Automatic
Transmission) on page 172.
If your vehicle has an Allison Transmission
®, the
transmission has a park pawl designed to hold the
higher weight of commercial medium duty
trucks. Therefore, the Allison Transmission
®uses
larger parts than other automatic transmissions.
These larger parts may sometimes make a
clunking noise when the selector lever is movedfrom DRIVE (D) or REVERSE (R) to PARK (P).
This is normal and there is no damage occurring
during these shifts.
If you cannot shift out of PARK (P), ease pressure
on the shift lever and push the shift lever all the
way up into PARK (P) as you maintain brake
application. Then, move the shift lever into
the gear you want.
If you ever hold the brake pedal down but still can
not shift out of PARK (P), try this:
1. Turn the key to ACCESSORY. There is no
shift interlock in this key position.
2. Apply and hold the brake until the end of
Step 4.
3. Shift the transmission to NEUTRAL (N).
4. Start the vehicle and then shift to the gear
you want.
5. Have the system xed as soon as you can.
172

Parking Over Things That Burn
{CAUTION:
Things that can burn could touch hot
exhaust parts under your vehicle and
ignite. Do not park over papers, leaves,
dry grass, or other things that can burn.
173

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:
Your exhaust system sounds strange
or different.
Your vehicle gets rusty underneath.
Your vehicle was damaged in a
collision.
CAUTION: (Continued)
CAUTION: (Continued)

Your vehicle was damaged when
driving over high points on the road
or over road debris.
Repairs were not done correctly.
Your vehicle or 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.
174

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
underEngine Exhaust on page 174.
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.
SeeWinter Driving on page 402.
{CAUTION:
It can be dangerous to get out of your
vehicle if the automatic transmission 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 it is on fairly
level ground, always set the parking brake
and move the automatic transmission
shift lever to PARK (P), or the manual
transmission shift lever to NEUTRAL.
175

{CAUTION:
Four-wheel drive vehicles with the transfer
case in NEUTRAL will allow the vehicle to
roll, even if your automatic transmission
shift lever is in PARK (P). So, be sure the
transfer case is in a drive gear — not in
NEUTRAL. Always set your parking brake.
Follow the proper steps to be sure your vehicle
will not move. SeeShifting Into Park (P)
(Automatic Transmission) on page 170.
If you are pulling a trailer, seeTowing a Trailer on
page 429.
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, 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.
176

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.
177

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 untilaZand
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.
178

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.
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 103.
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.
179

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.
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 for approximately four seconds
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.
180