2007 GMC SIERRA Owner's Manual

4n(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.
StabiliTrak
®will not engage in this mode.
{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.
SeeParking Brake on page 162.
N (NEUTRAL):Shift the vehicle’s transfer case to
NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 439or
Towing Your Vehicle on page 439for more
information.If the SERVICE 4–Wheel Drive message stays on,
you should take your vehicle to your dealer for
service. See “Service 4–Wheel Drive message”
underDIC Warnings and Messages on page 279.
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.
See Shifting Out of Four-Wheel-Drive Low for
more information.
Shifting Into Four-Wheel Drive Low
When Four-Wheel-Drive Low is engaged, vehicle
speed should be kept below 45 mph. Extended
high-speed operation in Four-Wheel-Drive Low may
damage or shorten the life of the drivetrain.
To shift to the Four-Wheel-Drive Low position, the
ignition must be in RUN and the vehicle must be
stopped or moving less than 3 mph (5 km/h) with
the transmission in NEUTRAL (N). The preferred
method for shifting into Four-Wheel-Drive Low
is to have your vehicle moving 1 to 2 mph
(1.6 to 3.2 km/h). Turn the knob to the
Four-Wheel-Drive Low position.
153

You must wait for the Four-Wheel-Drive Low
indicator light to stop ashing and remain on before
shifting your transmission in gear.
Notice:Shifting the transmission into gear
before the requested mode indicator light has
stopped ashing could damage the transfer
case. To help avoid damaging your vehicle,
always wait for the mode indicator lights
to stop ashing before shifting the
transmission into gear.
It is typical for your vehicle to exhibit signicant
engagement noise and bump when shifting
between Four-Wheel-Drive Low and
Four-Wheel-Drive High ranges or from NEUTRAL
with the engine running.
If the knob is turned to the Four-Wheel-Drive Low
position when your vehicle is in gear and/or
moving, the Four-Wheel-Drive Low indicator light
will ash for 30 seconds and not complete the
shift unless your vehicle is moving less than 3 mph
(5 km/h) and the transmission is in NEUTRAL (N).
After 30 seconds the transfer case will shift to
Four-Wheel-Drive High mode.Shifting Out of Four-Wheel-Drive Low
To shift from Four-Wheel-Drive Low to
Four-Wheel-Drive High, or Two-Wheel-Drive High,
your vehicle must be stopped or moving less
than 3 mph (5 km/h) with the transmission
in NEUTRAL (N) and the ignition in RUN. The
preferred method for shifting out of
Four-Wheel-Drive Low is to have your vehicle
moving 1 to 2 mph (1.6 to 3.2 km/h). Turn the knob
to the Four-Wheel-Drive High, or Two-Wheel-Drive
High position. You must wait for the
Four-Wheel-Drive High, or Two-Wheel-Drive High
indicator light to stop ashing and remain on
before shifting the transmission into gear.
Notice:Shifting the transmission into gear
before the requested mode indicator light has
stopped ashing could damage the transfer
case. To help avoid damaging your vehicle,
always wait for the mode indicator lights
to stop ashing before shifting the
transmission into gear.
It is typical for your vehicle to exhibit signicant
engagement noise and bump when shifting
between Four-Wheel-Drive Low and
Four-Wheel-Drive High ranges or from NEUTRAL
with the engine running.
154

If the knob is turned to the Four-Wheel-Drive High,
or Two-Wheel-Drive High switch position when
your vehicle is in gear and/or moving, the
Four-Wheel-Drive High, or Two-Wheel-Drive High
indicator light will ash for 30 seconds but will
not complete the shift unless your vehicle is
moving less than 3 mph (5 km/h) and the
transmission is in NEUTRAL (N).
Shifting into NEUTRAL
To shift the transfer case to 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 162for more information.
3. Start the vehicle or turn the ignition to RUN.
4. Shift the transmission to NEUTRAL (N).5. Shift the transfer case to
Two-Wheel-Drive High.
6. Turn the transfer case dial clockwise to
NEUTRAL till it stops and hold it for
10 seconds. Then slowly release the dial to
the four low position. The NEUTRAL light will
come on when the transfer case shift to
NEUTRAL is complete.
7. If the engine is running, verify that the
transmission is in NEUTRAL (N) by shifting
the transmission to REVERSE (R) for
one second, then shift the transmission to
DRIVE (D) for one second.
8. Turn the ignition to ACCESSORY, which will
turn the engine off.
9. Place the transmission shift lever in PARK (P).
10. Release the parking brake prior to moving
the vehicle.
11. Turn the ignition to LOCK.
155

Shifting Out of NEUTRAL
To shift out of NEUTRAL do the following:
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. Turn the transfer case dial to
Two-Wheel-Drive High.
After the transfer case has shifted out of
NEUTRAL the 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 your 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.
Automatic Transfer Case
The transfer case knob
is located next to the
steering column.
For information on StabiliTrak
®, seeStabiliTrak®
System on page 381.
156

Use the dial to shift into and out of
Four-Wheel Drive.
You can choose among ve driving settings:
Indicator lights in the dial show which setting you
are in. The indicator lights will come on briey
when you turn on the ignition and one will stay on.
If the lights do not come on, you should take
your vehicle to your dealer for service. An indicator
light will ash while shifting the transfer case. It
will remain illuminated when the shift is complete.
If for some reason the transfer case cannot
make a requested shift, it will return to the last
chosen setting.
2
m(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.AUTO (Automatic Four-Wheel Drive):This
setting is ideal for use when road surface traction
conditions are variable. When driving your
vehicle in AUTO, the front axle is engaged, but
the vehicle’s power is sent only to the front
and rear wheels automatically based on driving
conditions. Power is sent to the front and rear
wheels automatically based on driving conditions.
Driving in this mode results in slightly lower
fuel economy than Two-Wheel-Drive High.
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 your vehicle. This is
the best setting to use when plowing snow.
157

4n(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 if you are driving
off-road in deep sand, deep mud, deep snow, and
while climbing or descending steep hills.
StabiliTrak
®will not engage in this mode. See
StabiliTrak®System on page 381for more
information.
{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.
SeeParking Brake on page 162.N (NEUTRAL):Shift the vehicle’s transfer case to
NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 439or
Towing Your Vehicle on page 439for more
information.
If the SERVICE 4–Wheel Drive message stays on,
you should take your vehicle to your dealer for
service. See “Service 4–Wheel Drive message”
underDIC Warnings and Messages on page 279.
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, and the indicator light will ash while shifting.
It will remain on when the shift is completed.
158

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.
Shifting Into Four-Wheel-Drive Low
When Four-Wheel-Drive Low is engaged, vehicle
speed should be kept below 45 mph. Extended
high-speed operation in Four-Wheel-Drive
Low may damage or shorten the life of the
drivetrain.
To shift to the Four-Wheel-Drive Low position, the
ignition must be in RUN and the vehicle must
be stopped or moving less than 3 mph (5 km/h)
with the transmission in NEUTRAL (N). The
preferred method for shifting into Four-Wheel-Drive
Low is to have your vehicle moving 1 to 2 mph
(1.6 to 3.2 km/h). Turn the knob to the
Four-Wheel-Drive Low position. You must wait for
the Four-Wheel-Drive Low indicator light to
stop ashing and remain on before shifting your
transmission in gear.Notice:Shifting the transmission into gear
before the requested mode indicator light has
stopped ashing could damage the transfer
case. To help avoid damaging your vehicle,
always wait for the mode indicator lights
to stop ashing before shifting the
transmission into gear.
It is typical for your vehicle to exhibit signicant
engagement noise and bump when shifting
between Four-Wheel-Drive Low and
Four-Wheel-Drive High ranges or from NEUTRAL
with the engine running.
If the knob is turned to the Four-Wheel-Drive Low
position when your vehicle is in gear and/or
moving, the Four-Wheel-Drive Low indicator light
will ash for 30 seconds and not complete the
shift unless your vehicle is moving less than 3 mph
(5 km/h) and the transmission is in NEUTRAL (N).
After 30 seconds the transfer case will shift to
Four-Wheel-Drive High mode.
159

Shifting Out of Four-Wheel-Drive Low
To shift from Four-Wheel-Drive Low to
Four-Wheel-Drive High, AUTO or
Two-Wheel-Drive High, your vehicle must be
stopped or moving less than 3 mph (5 km/h) with
the transmission in NEUTRAL (N) and the
ignition in RUN. The preferred method for shifting
out of Four-Wheel-Drive Low is to have your
vehicle moving 1 to 2 mph (1.6 to 3.2 km/h). Turn
the knob to the Four-Wheel-Drive High, AUTO
or Two-Wheel-Drive High position. You must wait
for the Four-Wheel-Drive High, AUTO or
Two-Wheel-Drive High indicator light to stop
ashing and remain on before shifting your
transmission into gear.
Notice:Shifting the transmission into gear
before the requested mode indicator light has
stopped ashing could damage the transfer
case. To help avoid damaging your vehicle,
always wait for the mode indicator lights
to stop ashing before shifting the
transmission into gear.It is typical for your vehicle to exhibit signicant
engagement noise and bump when shifting
between Four-Wheel-Drive Low and
Four-Wheel-Drive High ranges or from 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 your 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 your vehicle is moving less than 3 mph
(5 km/h) and the transmission is in NEUTRAL (N).
Shifting into NEUTRAL
To shift the transfer case to 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 162
for more information.
160