2004 GMC SIERRA Owner's Manual

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
wasn't fully locked into PARK (P).
Torque Lock (Automatic Transmission)
If you are parking on a hill and you don't 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 ªtorque
lock.²To 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 ªShifting
Into PARK (P)².
When you are ready to drive, move the shift lever out of
PARK (P)
beforeyou release the parking brake.
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)
Your vehicle has an automatic transmission shift lock
control system which locks the shift lever in PARK 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. See
Automatic
Transmission Operation on page 2-26.
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't 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.
2-51

Parking Your Vehicle
{CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the manual
transmission is in gear. Your or someone else
could be seriously injured. Be sure to set the
parking brake before placing the transfer case
in NEUTRAL. See²Parking Brakeº in the Index.
Before you get out of your vehicle, move the shift lever
into REVERSE (R), and ®rmly apply the parking
brake. Once the shift lever has been placed into
REVERSE (R) with the clutch pedal pressed in, you can
turn the ignition key to LOCK, remove the key and
release the clutch.
If you are parking on a hill, or if you are pulling a trailer,
see
Towing a Trailer on page 4-70.
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.
2-52

Engine Exhaust
{CAUTION:
Engine exhaust can kill. It contains the gas
carbon monoxide (CO), which you can not 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.
·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 had been
modi®ed 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.
Running Your Engine While You
Are 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 2-53.
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 Ð with CO Ð 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 4-47.
2-53

{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 your
parking brake and move the shift lever to
PARK (P).
{CAUTION:
Four-wheel drive vehicles with the transfer
case in NEUTRAL will allow the vehicle to roll,
even if your shift lever is in PARK (P). So, be
sure the transfer case is in a drive gear Ð not
in NEUTRAL. Always set your parking brake.
Follow the proper steps to be sure your vehicle will not
move. See
Shifting Into Park (P) on page 2-49.
If you are pulling a trailer, see
Towing a Trailer on
page 4-70.
Mirrors
Manual Rearview Mirror
Pull the tab under the mirror toward you to reduce glare
from headlamps behind you after dark. Push the tab
away from you for normal daytime operation.
2-54

Automatic Dimming Rearview Mirror
with OnStar
ž, 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, brie¯y 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 ÉF, or ÉC
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.
2-55

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.
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 appears in the display. The compass
is now in zone mode.
2-56

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.
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 Air Bag Indicator
Your vehicle may be equipped with a passenger air bag
indicator, on the mirror glass, just above the buttons.
If your vehicle has this feature, the mirror will display the
word ON, or an air bag symbol in Canada, when the
passenger air bag is enabled. For more information, see
Passenger Sensing System on page 1-81.
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 your 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 brie¯y pressing either the TEMP
or the COMP button.
2-57

Temperature Display
The temperature can be displayed by pressing the
TEMP button. Pressing the TEMP button once brie¯y,
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 ÉF
and ÉC. 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.
Automatic Dimming Mirror Operation
The time period you need to press and hold the TEMP
button to turn the automatic dimming feature on or
off is approximately eight seconds. The indicator light to
the left of the TEMP button will still turn on or off to
show you when the automatic dimming feature is
activated. 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 COMP button once brie¯y 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, push
in the COMP button for approximately eight seconds
or until CAL is displayed.
2-58