2007 GMC SIERRA towing

Turn the tow/haul mode on and off by pressing the
button, located on the end of the shift lever.
When the tow/haul is on, a light on the instrument
panel cluster will come on.
SeeTow/Haul Mode Light on page 266for more
information.
Also see “Tow Haul Mode” underTowing a Trailer
on page 445for more information.
Grade Braking (Allison Transmission®
or Hydra-Matic®6-Speed Automatic
Transmission)
The Grade Braking shift modes can be activated
by pressing the button on the end of the shift
control lever. While in Range Selection Mode,
Grade Braking is deactivated allowing the driver to
select a desired range of gears.Grade Braking is only active while the Tow/Haul
Mode is selected and you are not in the Range
Selection Mode. See “Tow/Haul Mode listed
previously andAutomatic Transmission Operation
on page 138for more information on the Range
Selection Mode. Grade Braking assists in
maintaining desired vehicle speeds when driving
on downhill grades by automatically implementing
a shift schedule that utilizes the engine and
transmission to slow the vehicle. This reduces
wear on the braking system and increases control
of the vehicle. Grade Braking monitors vehicle
speed, acceleration, engine torque and brake
pedal usage. Using this information, it detects
when the truck is on a downhill grade and
the driver desires to slow the vehicle by pressing
the brake. See the diesel supplement for
information on Cruise Grade Braking.
Also seeTowing a Trailer on page 445for more
information.
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A Four-Wheel Drive
indicator light comes on
when you shift into
four-wheel drive and the
front axle engages.
SeeFour-Wheel-Drive
Light on page 265
Some delay between shifting and when the
indicator light comes on is normal.
Recommended Transfer Case Settings
Driving ConditionsTransfer Case Settings
2m4m4nN
Normal YES
Severe YES
Extreme YES
Vehicle in Tow* YES
*SeeRecreational Vehicle Towing on page 439
Towing Your Vehicle on page 439
Notice:Driving on clean, dry pavement in
four-wheel drive for an extended period of time
can cause premature wear on your vehicle’s
powertrain. Do not drive on clean, dry
pavement in Four-Wheel Drive for extended
periods of time.
4
n(Four-Wheel-Drive Low):This setting also
engages the front axle and delivers extra
torque. You may never need Four-Wheel-Drive
Low. 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. When operating in Four-Wheel Low,
the gear ratio provides additional torque when
compared to Four-Wheel-Drive High. The
transmission gear shift feel is exaggerated.
148

A parking brake symbol
is located next to the
N (NEUTRAL) symbol
as a reminder to set the
parking brake before
shifting the transfer case
in Neutral.
{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 to this setting only when
your vehicle needs to be towed. SeeRecreational
Vehicle Towing on page 439orTowing Your
Vehicle on page 439
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.
4
m(Four-Wheel-Drive High):Use this setting
when you need extra traction, 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.
You can shift from Two-Wheel-Drive High to
Four-Wheel-Drive High or Four-Wheel-Drive High
to Two-Wheel-Drive High while the vehicle is
moving. In extremely cold weather, it may
be necessary to stop or slow the vehicle to shift
into Four-Wheel-Drive High.
149

Electronic Transfer Case
The transfer case knob
is located next to the
steering column.
Use the dial to shift into and out of
four-wheel drive.
Recommended Transfer Case Settings
Driving ConditionsTransfer Case Settings
2m4m4nN
Normal YES
Severe YES
Extreme YES
Vehicle in Tow* YES
*SeeRecreational Vehicle Towing on page 439
Towing Your Vehicle on page 439
You can choose among four 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 ashes while shifting the transfer case and
remains 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.
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.
152

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

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

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 5 mph (8 km/h).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, seeTowing a Trailer on page 445.
162

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
CAUTION: (Continued)
CAUTION: (Continued)
lever is in PARK (P). So, be sure the
transfer case is in a drive gear — not in
NEUTRAL. If you are pulling a trailer, see
Towing a Trailer on page 445.
1. Hold the brake pedal down with your right foot
and set the parking brake.
2. Move the shift lever into the PARK (P)
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 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).
163