2009 GMC SIERRA brake

2m(Two-Wheel-Drive High):This setting is used for
driving in most street and highway situations. The front
axle is not engaged in Two-Wheel Drive. This setting also
provides the best fuel economy.
4
m(Four-Wheel-Drive High):Use the
Four-Wheel-Drive High position when extra
traction is needed, such as on snowy or icy roads
or in most off-road situations. This setting also engages
the front axle to help drive the vehicle. This is the best
setting to use when plowing snow.
4
n(Four-Wheel-Drive Low):This setting also engages
the front axle and delivers extra torque. You may never
need this setting. It sends maximum power to all four
wheels. You might choose Four-Wheel-Drive Low while
driving off-road in deep sand, deep mud, deep snow, and
while climbing or descending steep hills.
If the vehicle has StabiliTrak
®, shifting into
Four-Wheel-Drive Low will turn Traction Control and
StabiliTrak
®off. SeeStabiliTrak®System on page 4-6.
{CAUTION:
Shifting the transfer case to N (Neutral) can
cause the vehicle to roll even if the transmission
is in P (Park). You or someone else could be
seriously injured. Be sure to set the parking brake
before placing the transfer case in N (Neutral).
SeeParking Brake on page 2-50.
N (Neutral):Shift the vehicle’s transfer case
to N (Neutral) only when towing the vehicle.
SeeRecreational Vehicle Towing on page 4-45or
Towing Your Vehicle on page 4-45for more information.
If the SERVICE 4–Wheel Drive message stays on,
you should take the vehicle to your dealer/retailer
for service. See “Service 4–Wheel Drive message”
underDIC Warnings and Messages on page 3-66.
2-42

Shifting into Neutral
To shift the transfer case to N (Neutral) do the following:
1. Make sure the vehicle is parked so that it will not roll.
2. Set the parking brake and press and hold the
regular brake pedal. SeeParking Brake on
page 2-50for more information.
3. Start the vehicle or turn the ignition to ON/RUN.
4. Shift the transmission to N (Neutral).
5. Shift the transfer case to Two-Wheel-Drive High.
6. Turn the transfer case dial clockwise to N (Neutral)
until it stops and hold it there until the Neutral light
starts blinking. This will take at least 10 seconds.
Then slowly release the dial to the four low position.
The N (Neutral) light will come on when the transfer
case shift to N (Neutral) is complete.
7. If the engine is running, verify that the transfer
case is in N (Neutral) by shifting the transmission
to R (Reverse) for one second, then shift the
transmission to D (Drive) for one second.
8. Turn the ignition to ACC/ACCESSORY, which will
turn the engine off.
9. Place the transmission shift lever in P (Park).
10. Release the parking brake prior to moving the
vehicle.
11. Turn the ignition to LOCK/OFF.
Shifting Out of Neutral
To shift the transfer case out of N (Neutral) do the
following:
1. Set the parking brake and apply the regular
brake pedal.
2. Turn the ignition to ON/RUN with the engine off,
and shift the transmission to N (Neutral).
3. Turn the transfer case dial to Two-Wheel-Drive High.
After the transfer case has shifted out of N (Neutral),
the N (Neutral) light will go out.
4. Release the parking brake prior to moving the
vehicle.
Notice:Shifting the transmission into gear before
the requested mode indicator light has stopped
ashing could damage the transfer case. To help
avoid damaging the vehicle, always wait for the mode
indicator lights to stop ashing before shifting the
transmission into gear.
5. 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.
2-45

If the vehicle has StabiliTrak®, shifting into
Four-Wheel-Drive Low will turn Traction Control and
StabiliTrak
®off. SeeStabiliTrak®System on page 4-6.
{CAUTION:
Shifting the transfer case to N (Neutral) can
cause the vehicle to roll even if the transmission
is in P (Park). You or someone else could be
seriously injured. Be sure to set the parking brake
before placing the transfer case in N (Neutral).
SeeParking Brake on page 2-50.
N (Neutral):Shift the vehicle’s transfer case
to N (Neutral) only when towing the vehicle. See
Recreational Vehicle Towing on page 4-45orTowing
Your Vehicle on page 4-45for more information.If the SERVICE 4-Wheel Drive message stays on,
you should take the vehicle to your dealer/retailer
for service. See “Service 4-Wheel Drive message”
underDIC Warnings and Messages on page 3-66.
Shifting Into Four-Wheel-Drive High
or AUTO (Automatic Four-Wheel Drive)
Turn the knob to the Four-Wheel-Drive High or AUTO
position. This can be done at any speed, except when
shifting from Four-Wheel-Drive Low. The indicator light
will ash while shifting. It will remain on when the shift is
completed.
Shifting Into Two-Wheel-Drive High
Turn the knob to the Two-Wheel-Drive High position.
This can be done at any speed, except when shifting
from Four-Wheel-Drive Low. The indicator light will
ash while shifting. It will remain on when the shift
is completed.
2-47

Notice:Shifting the transmission into gear before
the requested mode indicator light has stopped
ashing could damage the transfer case. To help
avoid damaging the vehicle, always wait for the
mode indicator lights to stop ashing before shifting
the transmission into gear.
It is typical for the vehicle to exhibit signicant
engagement noise and bump when shifting between
Four-Wheel-Drive Low and Four-Wheel-Drive High
ranges or from N (Neutral) with the engine running.
If the knob is turned to the Four-Wheel-Drive
High, AUTO, or Two-Wheel-Drive High switch
position when the vehicle is in gear and/or moving,
the Four-Wheel-Drive High, AUTO or Two-Wheel-Drive
High indicator light will ash for 30 seconds but will not
complete the shift unless the vehicle is moving less than
3 mph (5 km/h) and the transmission is in N (Neutral).
Shifting into Neutral
To shift the transfer case to N (Neutral) do the following:
1. Make sure the vehicle is parked so that it will not roll.
2. Set the parking brake and apply the regular brake
pedal. SeeParking Brake on page 2-50for more
information.3. Start the vehicle or turn the ignition to ON/RUN.
4. Put the transmission in N (Neutral).
5. Shift the transfer case to Two-Wheel Drive High.
6. Turn the transfer case dial clockwise to N (Neutral)
until it stops and hold it there until the N (Neutral)
light starts blinking. This will take at least
10 seconds. Then slowly release the dial to the
four low position. The N (Neutral) light will come
on when the transfer case shift to N (Neutral) is
complete.
7. If the engine is running, make sure that the transfer
case is in N (Neutral) by shifting the transmission
to R (Reverse) for one second, then shift the
transmission to D (Drive) for one second.
8. Turn the ignition to ACC/ACCESSORY, which will
turn the engine off.
9. Place the transmission shift lever in P (Park).
10. Release the parking brake prior to moving the
vehicle.
11. Turn the ignition to LOCK/OFF.
2-49

Shifting Out of Neutral
To shift out of N (Neutral) do the following:
1. Set the parking brake and apply the regular
brake pedal.
2. Turn the ignition to ON/RUN with the engine off,
and shift the transmission to N (Neutral).
3. Turn the transfer case dial to Two-Wheel-Drive
High, Four-Wheel-Drive High, AUTO.
After the transfer case has shifted out of N (Neutral),
the N (Neutral) light will go out.
4. Release the parking brake prior to moving the
vehicle.
Notice:Shifting the transmission into gear before
the requested mode indicator light has stopped
ashing could damage the transfer case. To help
avoid damaging the vehicle, always wait for the
mode indicator lights to stop ashing before
shifting the transmission into gear.
5. Start the engine and shift the transmission to the
desired position.
Parking Brake
For vehicles with a release handle, set the parking
brake by holding the regular brake pedal down, then
pushing down the parking brake pedal.
If the ignition is on, the brake system warning light will
come on. SeeBrake System Warning Light on page 3-42.
A chime sounds and the warning light ashes when
the parking brake is applied and the vehicle is moving
at least 5 mph (8 km/h).
To release the parking brake, hold the regular brake
pedal down. Then pull the bottom edge of the lever with
the parking brake symbol, located above the parking
brake pedal.
2-50

If the ignition is on when the parking brake is released,
the brake system warning light goes off.
Notice:Driving with the parking brake on can
overheat the brake system and cause premature
wear or damage to brake system parts. Make sure
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,
seeTowing a Trailer on page 4-51.
For vehicles without a release handle, set the parking
brake by holding the regular brake pedal down, then
pushing down the parking brake pedal.If the ignition is on, the brake system warning light will
come on. SeeBrake System Warning Light on page 3-42.
Notice:Driving with the parking brake on can
overheat the brake system and cause premature
wear or damage to brake system parts. Make sure
that the parking brake is fully released and the brake
warning light is off before driving.
To release the parking brake, hold the regular brake
pedal down, then push down momentarily on the parking
brake pedal until you feel the pedal release. Slowly pull
your foot up off the park brake pedal. If the parking brake
is not released when you begin to drive, the brake system
warning light will ash and a chime will sound warning
you that the parking brake is still on.
If you are towing a trailer and are parking on a hill,
seeTowing a Trailer on page 4-51.
2-51

Shifting Into Park
{CAUTION:
It can be dangerous to get out of the vehicle if the
shift lever is not fully in P (Park) with the parking
brake rmly set. The vehicle can roll. If you have left
the engine running, the vehicle can move suddenly.
You or others could be injured. To be sure the
vehicle will not move, even when you are on fairly
level ground, use the steps that follow. With
four-wheel drive, if the transfer case is in Neutral,
the vehicle will be free to roll, even if the shift lever
is in P (Park). So, be sure the transfer case is in a
drive gear — not in Neutral. If you are pulling a
trailer, seeTowing a Trailer on page 4-51.1. Hold the brake pedal down, then set the
parking brake.
SeeParking Brake on page 2-50for more
information.
2. Move the shift lever into the P (Park) position by
pulling the shift lever toward you and moving it up
as far as it will go.
3. Be sure the transfer case is in a drive gear — not
in N (Neutral).
4. Turn the ignition key to LOCK/OFF.
5. Remove the key and take it with you. If you can
leave the vehicle with the ignition key in your
hand, the vehicle is in P (Park).
2-52

Leaving the Vehicle With the Engine
Running
{CAUTION:
It can be dangerous to leave the vehicle with the
engine running. The vehicle could move suddenly
if the shift lever is not fully in P (Park) with the
parking brake rmly set.
If you have four-wheel drive and the transfer case
is in Neutral, the vehicle will be free to roll, even
if the shift lever is in P (Park). 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
the vehicle with the engine running unless you
have to.If you have to leave the vehicle with the engine running,
be sure your vehicle is in P (Park) and the parking brake
is rmly set before you leave it. After you move the shift
lever into P (Park), hold the regular brake pedal down.
Then, see if you can move the shift lever away from
P (Park) without rst pulling it toward you. If you can,
it means that the shift lever was not fully locked into
P (Park).
Torque Lock
If you are parking on a hill and you do not shift your
transmission into P (Park) 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 P (Park). This is called torque lock. To
prevent torque lock, set the parking brake and then shift
into P (Park) properly before you leave the driver seat.
To nd out how, seeShifting Into Park on page 2-52.
When you are ready to drive, move the shift lever out of
P (Park) before you 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,
then you will be able to pull the shift lever out of P (Park).
2-53