2007 GMC SIERRA tow

Range Selection Mode (Allison®or
Hydra-Matic®6-Speed Transmission)
Your vehicle may have a Range Selection Mode.
The Range Selection Mode helps control the
vehicle’s transmission and vehicle speed while
driving down hill or towing a trailer by letting
you select a desired range of gears.To use this feature, do the following:
1. Move the shift lever to the MANUAL
MODE (M).
2. Press the plus/minus buttons, located on the
steering column shift lever, to select the
desired range of gears for your current
driving conditions.
When MANUAL MODE (M) is selected a number
displays next to the M, indicating the current gear.
This number is the highest gear that can be used.
However, your vehicle can automatically shift to
lower gears as it adjusts to driving conditions. This
means that all gears below that number are
available. When FIFTH (5) is selected, FIRST (1)
through FIFTH (5) gears are automatically shifted
by the vehicle, but SIXTH (6) cannot be used until
the plus/minus button located on the steering
column lever is used to change to the gear.
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Grade Braking is not available when the Range
Selection Mode is active. SeeTow/Haul Mode on
page 144.
While using the Range Selection mode feature,
cruise control and the Tow/Haul mode can
be used.
Notice:Spinning the tires or holding the
vehicle in one place on a hill using only the
accelerator pedal may damage the
transmission. The repair will not be covered by
your warranty. If you are stuck, do not spin
the tires. When stopping on a hill, use the
brakes to hold the vehicle in place.
Low Traction Mode
If your vehicle has the Allison Transmission®,or
the Hydra-Matic®6-Speed Automatic
Transmission, it has a Low Traction Mode that
assist in vehicle acceleration when road conditions
are slippery, such as with ice or snow. While
the vehicle is at a stop, select the second gear
range using the Range Selection system. This will
limit torque to the wheels after it detects wheel
slip, preventing the tires from spinning.
Tow/Haul Mode
If your vehicle has an automatic transmission, it
has a tow/haul mode. If your vehicle has an Allison
or Hydra-Matic
®6-speed automatic transmission
see “Tow/Haul Mode (Allison or Hydra-Matic®
6-Speed Automatic Transmission®) following.
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The tow/haul mode adjusts the transmission shift
pattern to reduce shift cycling, providing
increased performance, vehicle control, and
transmission cooling when towing or hauling
heavy loads.
The selector button is located on the end of
the shift lever. Turn the tow/haul on and off by
pressing the button. 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.Tow/Haul Mode (Allison Transmission®
or Hydra-Matic®6-Speed Automatic
Transmission)
If your vehicle has an Allison or Hydra-Matic®
6-speed automatic transmission®, it has a tow/haul
mode. The tow/haul mode adjusts the transmission
shift pattern to reduce shift cycling, providing
increased performance, vehicle control, and
transmission cooling when towing or hauling
heavy loads.
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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.
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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.
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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.
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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.
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