To use this feature, do the following:
1. Move the shift lever to the MANUAL MODE (M).
When in the MANUAL MODE, the transmission’s
current gear range will be the highest attainable
range with all the lower gears available.
2. Press the plus/minus buttons to upshift or downshift
selecting the desired range of gears for your current
driving conditions.
The Range Selection Mode allows you to control the
vehicle’s engine and vehicle speed while driving
down hill by allowing you to select a desired gear.
The DIC shows the six available ranges with the highest
attainable range shown in brackets. SeeDriver
Information Center (DIC) on page 3-51andDIC
Operation and Displays on page 3-52for more
information.
While using the Range Selection mode feature, cruise
control and the Tow/Haul mode can be used.
Low Traction Mode
(Allison Transmission®)
If your vehicle has the DURAMAX®diesel engine and
the Allison Transmission®, it is equipped with a Low
Traction Mode that assists in vehicle acceleration when
road conditions are slippery, such as ice or snow.While at a stop, selecting the second gear range using
the Range Selection system, will allow the Allison
Transmission
®to limit torque to the wheels after it
detects wheel slip, preventing the tires from spinning.
Notice:Spinning the tires or holding the vehicle in
one place on a hill using only the accelerator
pedal may damage the transmission. If you are
stuck, do not spin the tires. When stopping on a hill,
use the brakes to hold the vehicle in place.
Cold Weather Operation
(Allison Transmission®)
On cold days, approximately 32°F (0°C) or colder, your
automatic transmission is designed to shift differently.
The transmission uses a warm-up mode shift schedule
until the engine reaches normal operating temperature.
While the transmission is in warm-up mode it is
normal for transmission upshifts to be delayed or held
longer. This feature improves heater performance
by giving quicker vehicle warm-ups.
When temperatures are below−13°F (−25°C), the
transmission will prevent certain operations to protect
against damage. When active the DIC will display
the message “Trans in Warm-up”.
SeeDIC Warnings and Messages on page 3-54for
more information.
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Tow/Haul Mode
If your vehicle has an automatic transmission, it may
have a Tow/Haul mode. If your vehicle has an Allison
Transmission
®see “Tow/Haul Mode (Allison
Transmission®) following. 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 Turn 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 3-49for more
information.If your vehicle is equipped with the Performance
Package-Enhanced Towing, activating the manual
selectable ride will adjust the shock absorber
characteristics to enhance the ride and handling of the
vehicle for towing or hauling heavy loads.
Also see Tow Haul Mode underTowing a Trailer on
page 4-67for more information.
Tow/Haul Mode (Allison Transmission®)
If your vehicle has an Allison Transmission®,itmay
have a Tow/Haul mode. 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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The selector button is located on the end of the shift
lever. Turn the Turn 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 3-49for more
information.
Also see “Tow Haul Mode” underTowing a Trailer on
page 4-67for more information.
Grade Braking and Cruise Grade
Braking (Allison Transmission®)
Grade Braking and Cruise Grade Braking assists when
driving on a downhill grade. It maintains the vehicle’s
speed by automatically implementing a shift schedule
that uses the engine and the transmission to slow
the vehicle. This reduces wear on the brakes system
and increases control of the vehicle. The system
constantly monitors the vehicle’s speed, acceleration,
engine torque, and brake pedal usage. It detects
when the truck is on a downhill grade and the driver’s
desire to slow down by pressing the brake.Cruise Grade Braking is available on the 6.6L
DURAMAX
®diesel engine. Cruise Grade Braking
monitors a vehicle’s cruise state, engine torque,
acceleration, vehicle speed, and the cruise set speed.
Using this information, it detects when the truck is
accelerating on a downhill grade and will automatically
downshift to slow the vehicle if it exceeds the cruise
set speed by a certain amount.
SeeCruise Control on page 3-10for more information.
The Tow/Haul mode and Grade Braking shift modes
can be activated by pressing the button on the front
of the shift control stalk. If your vehicle has the
DURAMAX
®Diesel Engine or the 8.1L VORTEC™
gasoline engine, Grade Braking is only available while
the Tow/Haul Mode is selected. While in the Range
Selection Mode, Grade Braking is deactivated allowing
the driver to select a desired gear.
SeeAutomatic Transmission Operation on page 2-24for
more information.
Also seeTowing a Trailer on page 4-67for more
information.
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Manual Transmission Operation
Five-Speed (VORTEC™ 6.0L V8 Engine)
Here is how to operate
your transmission.
FIRST (1) is intended only for heavy loads or trailer
towing and is not recommended for normal driving.
During the rst 500 miles (805 km) of vehicle use, start
your vehicle moving in FIRST (1). This allows clutch
components to break-in properly.
FIRST (1):Press the clutch pedal and shift into
FIRST (1). Then, slowly let up on the clutch pedal as
you press the accelerator pedal. Shift into FIRST (1)
only when the vehicle is below 5 mph (8 km/h). If you
try to shift down into FIRST (1) at excessive vehicle
speeds, the shift lever will not move into FIRST (1)
until vehicle speed is reduced.SECOND (2):Press the clutch pedal and shift into
SECOND (2). Then, slowly let up on the clutch pedal as
you press the accelerator pedal.
You can shift into SECOND (2) when you are going less
than 20 mph (32 km/h). If you have come to a complete
stop and it is hard to shift into SECOND (2), put the
shift lever into NEUTRAL and let up on the clutch.
Press the clutch pedal back down. Then shift into
SECOND (2). If you try to downshift into SECOND (2) at
excessive vehicle speeds, the shift lever will not move
into the SECOND (2) position until the vehicle speed
is reduced.
THIRD (3):Press the clutch pedal and shift into
THIRD (3). Then, slowly let up on the clutch pedal as
you press the accelerator pedal.
FOURTH (4) and FIFTH (5):Shift into the higher
forward gears the same way you do for THIRD (3).
Slowly let up on the clutch pedal as you press the
accelerator pedal.
To stop, let up on the accelerator pedal and press the
brake pedal. Just before the vehicle stops, press
the clutch pedal and the brake pedal, and shift to
NEUTRAL.
NEUTRAL:Use this position when you start or idle
your engine.
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Six-Speed (VORTEC™ 8.1L V8 and
DURAMAX®6.6L V8 Engines)
Here is how to operate
your transmission.
This six-speed pattern is unique to GM manual
transmissions. The transmission always repositions the
shift lever to NEUTRAL, which is located between
FOURTH (4) and FIFTH (5) gear.
To prevent unintentional gear selections, additional
force is required to move the shift lever into
REVERSE (R) or FIRST (1). Use FIRST (1) when trailer
towing, driving with payload in the pickup box or
launching on a grade. Otherwise, start in SECOND (2)
gear. Only shift into FIRST (1) when the vehicle has
stopped moving.During the rst 500 miles (805 km) of vehicle use, start
the vehicle moving in FIRST (1) gear. This allows
the clutch components to wear-in properly.
FIRST (1):With the vehicle at a stop, release the
brake, press the clutch pedal and shift into FIRST (1).
Then, slowly let up on the clutch pedal as you press the
accelerator pedal. Only downshift into FIRST (1)
when the vehicle has come to a complete stop. If the
shift lever will not go into FIRST (1), put the lever
in NEUTRAL and let up on the clutch pedal to fully
engage the clutch. Press the clutch pedal again. Then,
shift into FIRST (1).
SECOND (2):With the vehicle at a stop, release the
brake, press the clutch pedal and shift into SECOND (2).
Then, slowly let up on the clutch pedal as you press
the accelerator pedal. With the vehicle moving, press the
clutch pedal and upshift into SECOND (2) from
FIRST (1) while applying light pressure to the right on
the shifter. Then, slowly let up on the clutch pedal
as you press the accelerator pedal. If you come to a
complete stop and the shift lever will not go into
SECOND (2), put the lever in NEUTRAL and let up on
the clutch pedal to fully engage the clutch. Press
the clutch pedal again. Then, shift into SECOND (2).
THIRD (3):Press the clutch pedal and upshift into
THIRD (3). Then, slowly let up on the clutch pedal as
you press the accelerator pedal.
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