2004 GMC SIERRA tow

6. Simultaneously press and hold the 2HI and 4LO
buttons for 10 seconds. The red NEUTRAL light
will come on when the transfer case shift to
NEUTRAL is complete.
7. Shift the transmission to REVERSE (R) for one
second, then shift the transmission to DRIVE (D)
for one second.
8. Turn the ignition to OFF.
9. Place the transmission shift lever in PARK (P).
10. Release the parking brake prior to towing.
Shifting Out of NEUTRAL
To shift out of NEUTRAL:
1. Set the parking brake and apply the regular brake
pedal.
2. Shift the transmission to NEUTRAL (N) and turn the
ignition to RUN with the engine off.
3. Press the button for the desired transfer case shift
position (2HI, 4HI, or 4LO).4. After the transfer case has shifted out of NEUTRAL
the red light will go out.
5. Release the parking brake.
6. You may start the engine and shift the transmission
to the desired position.
Excessively shifting the transfer case into or out of the
different modes may cause the transfer case to enter the
shift protection mode. This will protect the transfer case
from possible damage and will only allow the transfer
case to respond to one shift per 10 seconds. The transfer
case may stay in this mode for up to three minutes.
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Parking Brake
To set the parking brake, hold the regular brake pedal
down with your right foot. Push down the parking
brake pedal with your left foot.
A chime will activate and the warning light will ¯ash
when the parking brake is applied and the vehicle
is moving at least 3 mph (5 km/h) for at least
three seconds.To release the parking brake, hold the regular brake
pedal down. Pull the bottom edge of the lever, located
above the parking brake pedal, with the parking
brake symbol, to release the parking brake.
If the ignition is on when the parking brake is released,
the brake system warning light will go off.
Notice:Driving with the parking brake on can
overheat the brake system and cause premature
wear or damage to brake system parts. Verify that
the parking brake is fully released and the brake
warning light is off before driving.
If you are towing a trailer and are parking on any hill,
see
Towing a Trailer on page 4-70.
2-48

Shifting Into Park (P)
{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. 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, use the steps that follow. With
four-wheel drive, if 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 Ð not
in NEUTRAL. If you are pulling a trailer, see
Towing a Trailer on page 4-70.
1. Hold the brake pedal down with your right foot and
set the parking brake.2. Move the shift lever into PARK (P) position like this:
·Pull the shift lever toward you.
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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.
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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

{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

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

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 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 de¯ectors and add-on
convex mirror attachments may adversely affect mirror
performance.
Outside Camper-Type Mirrors
If your vehicle is equipped with camper-type mirrors,
they can be adjusted so you can have a clear view
of the objects behind you.
Pull out the mirror head to extend it for better visibility
when towing a trailer.
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