2004 GMC SIERRA ignition

g(4LO):This setting also engages your front axle to
give you extra traction. You may never need 4LO. It
sends the maximum power to all four wheels. You might
choose 4LO if you were driving off-road in sand, mud
or deep snow and climbing or descending steep hills.
Indicator lights in the switches show you which
setting you are in. The indicator lights will come on
brie¯y when you turn on the ignition and the last chosen
setting will stay on. If the lights do not come on, you
should take your vehicle in for service. An indicator light
will ¯ash while shifting. It will remain illuminated when
the shift is completed. If for some reason the transfer
cannot make a requested shift, it will return to the
last chosen setting.
{CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the
transmission is in PARK (P). You or someone
else could be seriously injured. Be sure to set
the parking brake before placing the transfer
case in NEUTRAL. See
Parking Brake on
page 2-48
.
NEUTRAL:Shift the vehicle's transfer case to
NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 4-54orTowing
Your Vehicle on page 4-53for more information.
Shifting from 2HI to 4HI
Press and release the 4HI switch. This can be done at
any speed, and the front axle will lock automatically
with some delay.
Shifting from 4HI to 2HI
Press and release the 2HI switch. This can be done at
any speed, and the front axle will unlock automatically
with some delay.
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Shifting from 2HI or 4HI to 4LO
To shift from 2HI or 4HI to 4LO, the vehicle must be
stopped or moving less than 3 mph (4.8 km/h) with the
transmission in NEUTRAL (N). The preferred method
for shifting into 4LO is to have your vehicle moving
1 to 2 mph (1.6 to 3.2 km/h). Press and release the
4LO switch. You must wait for the 4LO indicator light to
stop ¯ashing and remain illuminated before shifting
your transmission into gear.
Notice:Shifting the transmission into gear before
the 4LO indicator light has stopped ¯ashing
could damage the transfer case. To help avoid
damaging your vehicle, always wait for the
4LO indicator light to stop ¯ashing before shifting
the transmission into gear.
If the 4LO switch is pressed when your vehicle is in
gear and/or moving, the 4LO indicator light will ¯ash for
30 seconds and not complete the shift unless your
vehicle is moving slower than 3 mph (4.8 km/h) and the
transmission is in NEUTRAL (N). The transfer case
will shift to 4HI while waiting to complete the shift.
Shifting from 4LO to 4HI or 2HI
To shift from 4LO to 4HI or 2HI, your vehicle must be
stopped or moving less than 3 mph (4.8 km/h) with
the transmission in NEUTRAL (N). The preferred method
for shifting out of 4LO is to have your vehicle moving
1 to 2 mph (1.6 to 3.2 km/h). Press and release the 4HI
switch. You must wait for the 4HI indicator light to
stop ¯ashing and remain illuminated before shifting your
transmission into gear.
If the 4HI switch is pressed when your vehicle is in gear
and/or moving, the 4HI indicator light will ¯ash for
30 seconds but will not complete the shift unless the
vehicle is moving slower than 3 mph (4.8 km/h) and the
transmission is in NEUTRAL (N).
Shifting into NEUTRAL
To shift the transfer case to NEUTRAL, ®rst make sure
the vehicle is parked so that it will not roll:
1. Set the parking brake.
2. Start the vehicle or turn the ignition to RUN.
3. Connect the vehicle to the towing vehicle.
4. Put the transmission in NEUTRAL (N).
5. Shift the transfer case to 2HI.
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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.
2-47

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.
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·Move the lever up as far as it will go.
3. Be sure the transfer case is in a drive gear ± not in
NEUTRAL (N).
4. Turn the ignition key to LOCK.
5. Remove the key and take it with you. If you can
leave your vehicle with the ignition key in your
hand, your vehicle is in PARK (P).
Leaving Your Vehicle With
the Engine Running (Automatic
Transmission Only)
{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 with a manual
transfer case shift lever 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. Don't leave
your vehicle with the engine running unless
you have to.
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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

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.
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