2009 HUMMER H2 tow

Automatic Transmission Operation
The vehicle has a Hydra-Matic®6L80 automatic
transmission, and has an electronic shift position
indicator within the instrument panel cluster.
This display comes on when the ignition key is
turned to the ON/RUN position.
There are several different positions for the shift lever.
P (Park):This position locks the rear wheels. It is the
best position to use when starting the engine because
the vehicle cannot move easily.
When parked on a hill, especially when the vehicle has
a heavy load, you may notice an increase in the effort
to shift out of P (Park). See Torque Lock (Automatic
Transmission) underShifting Into Park on page 2-43
for more information.{CAUTION:
It is 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.
Do not leave the vehicle when the engine is
running unless you have to. 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, always set the parking brake and
move the shift lever to P (Park). SeeShifting Into
Park on page 2-43. If you are pulling a trailer, see
Towing a Trailer on page 4-55.
R (Reverse):Use this gear to back up.
Notice:Shifting to R (Reverse) while the vehicle is
moving forward could damage the transmission.
The repairs would not be covered by the vehicle
warranty. Shift to R (Reverse) only after the vehicle
is stopped.
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To rock the vehicle back and forth to get out of snow,
ice, or sand without damaging the transmission, seeIf
Your Vehicle is Stuck in Sand, Mud, Ice, or Snow on
page 4-39.
N (Neutral):In this position, the engine does not
connect with the wheels. To restart the engine when
the vehicle is already moving, use N (Neutral) only.
Also, use N (Neutral) when the vehicle is being towed.
{CAUTION:
Shifting into a drive gear while the engine is
running at high speed is dangerous. Unless your
foot is rmly on the brake pedal, the vehicle could
move very rapidly. You could lose control and hit
people or objects. Do not shift into a drive gear
while the engine is running at high speed.
Notice:Shifting out of P (Park) or N (Neutral) with
the engine running at high speed may damage the
transmission. The repairs would not be covered by
the vehicle warranty. Be sure the engine is not
running at high speed when shifting the vehicle.D (Drive):This position is for normal driving. It provides
the best fuel economy. If you need more power for
passing, and you are:
Going less than about 35 mph (55 km/h), push the
accelerator pedal about halfway down.
Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
By doing this, the vehicle shifts down to the next gear
and has more power.
D (Drive) can be used when towing a trailer, carrying a
heavy load, driving on steep hills, or for off-road driving.
You may want to shift the transmission to a lower gear
selection if the transmission shifts too often.
Downshifting the transmission in slippery road conditions
could result in skidding, see Skidding underLoss of
Control on page 4-13.
M (Manual Mode):This position lets the driver select
the range of gears appropriate for current driving
conditions. If the vehicle has this feature, see Driver
Shift Control (DSC) later in this section.
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 the vehicle warranty. If you are stuck, do
not spin the tires. When stopping on a hill, use the
brakes to hold the vehicle in place.
2-33

Driver Shift Control (DSC)
The vehicle has Driver Shift Control (DSC). DSC
controls the transmission and vehicle speed while driving
down hill or towing a trailer by allowing you to select
a desired range of gears.
To use this feature:
1. Move the shift lever to the M (Manual Mode).
This will force a downshift from the current gear,
for gears 3 through 6.
2. Press the (+) plus or (−) minus button on the left
side of the steering wheel, to select the desired
range of gears for current driving conditions.When in the M (Manual Mode) a number will display
next to the M, indicating the maximum available gear.
The DIC display will show the message MANUAL SHIFT
on the rst line and the maximum available gear will be
displayed on the second line. SeeDriver Information
Center (DIC) on page 3-46andDIC Operation and
Displays (Using DIC Buttons) on page 3-47orDIC
Operation and Displays (Using Trip Odometer Reset
Stem) on page 3-52for more information. The number
displayed in the DIC is the highest gear available.
The transmission will be limited to the gear selected and
lower gears. Shifting will occur normally while driving,
however the cluster will continue to display the maximum
available gear. Higher gears will not be available unless
the selection is changed to include higher gears using
the (+) plus button.
Grade Braking is not available when the Driver Shift
Control is active. SeeTow/Haul Mode on page 2-36and
Towing a Trailer on page 4-55for more information.
While using the DSC, cruise control and the tow/haul
mode can be used.
2-35

Tow/Haul Mode
The vehicle 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 while towing or
hauling heavy loads.
Press the button located on the instrument panel to the
right of the steering wheel to turn tow/haul on or off. While
tow/haul is on, a light on the instrument panel cluster
comes on.
SeeTow/Haul Mode Light on page 3-44for more
information.
Also see “Tow Haul Mode” underTowing a Trailer on
page 4-55for more information.
Grade Braking
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 2-32for 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.
Also seeTowing a Trailer on page 4-55for more
information.
2-36

Cruise Grade Braking
Cruise Grade Braking operates while Cruise Control
is engaged in Tow/Haul mode to assist in maintaining
vehicle speed under loaded vehicle conditions. Cruise
Grade Braking assists when driving on a downhill grade.
It maintains vehicle speed by automatically implementing
a shift schedule that uses the engine and the
transmission to slow the vehicle. If vehicle speed is
above the desired speed the transmission will downshift
to slow the vehicle. If vehicle speed is near or below
desired speed the trans will upshift, allowing vehicle
speed to increase.
While in the Range Select Mode (RSM) mode, cruise
grade braking is not available.
SeeAutomatic Transmission Operation on page 2-32.
Full-Time Four-Wheel Drive
The Full-Time Four-Wheel Drive transfer case is
designed to constantly send the engine’s driving power
to all four wheels for extra traction. To get the most
out of Full-Time Four-Wheel Drive, you must be familiar
with its operation.
Notice:Driving on pavement in Four-Wheel
High Lock or Four Wheel Low Lock for extended
periods may cause premature wear on the vehicle
powertrain and tires. Do not drive in Four-Wheel
High Lock or Four-Wheel Low Lock on pavement
for extended periods.
2-37

N (Neutral):Shift the transfer case to N (Neutral) only
when towing the vehicle. SeeRecreational Vehicle
Towing on page 4-50orTowing Your Vehicle on
page 4-50for more information.
Indicator lights in the dial show which mode 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, take the vehicle to your dealer/retailer for service.
An indicator light will ash while shifting the transfer case.
It will remain on when the shift is complete. If the transfer
case cannot make a requested shift, it will return to the
last chosen setting.
If the SERVICE 4WD message stays on, you should
take the vehicle to your dealer/retailer for service.
See “Service 4WD message” underDriver Information
Center (DIC) on page 3-46.
Shifting between Four-Wheel High and
Four-Wheel-High Lock
With the vehicle traveling less than 40 mph
(64 km/h), turn the dial to the Four-Wheel High or
Four-Wheel-High Lock position. The indicator light
on the dial will ash while shifting. It will remain on
when the shift is complete.
It may be necessary to drive backwards for a short
distance of 25 feet (7.5 m) to get the lock feature
to disengage.
Shifting into Four-Wheel-Low Lock
To shift into Four-Wheel-Low Lock, the ignition must be
in ON/RUN and the vehicle must be stopped or moving
less than 3 mph (5 km/h) with the transmission in
N (Neutral). The preferred method for shifting into
Four-Wheel Low Lock is to have the vehicle moving
1 to 2 mph (1.6 to 3.2 km/h). Turn the dial to the
Four-Wheel-Low Lock position. You must wait for the
Four-Wheel-Low Lock indicator light on the dial to stop
ashing and remain lit before shifting the transmission
in gear.
When the transfer case is shifted into the
Four-Wheel-Low Lock position a StabiliTrak
®indicator
light will come on to show that the system has been
turned off and a message will show in the DIC.
SeeDIC Warnings and Messages on page 3-56
for more information.
Notice:Shifting the transmission into gear before
the indicator light stops ashing could cause
damage to the transfer case. Always wait until the
indicator light stops ashing before putting the
transmission back in gear.
It is normal for the vehicle to have engagement noise
and bump when shifting between Four-Wheel Low Lock,
Full-Time Four-Wheel Drive or Four-Wheel-High Lock
ranges or from N (Neutral) with the engine running.
2-39

Parking Brake
To set the parking brake, hold the regular brake pedal
down and push down the parking brake pedal.
A chime will activate and the warning light will ash
when the parking brake is applied and the vehicle
is moving at least 3 mph (5 km/h) for at least
three seconds.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. 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 4-55.
2-42

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.
If you are pulling a trailer, seeTowing a Trailer
on page 4-55.
1. Hold the brake pedal down and set the parking
brake. SeeParking Brake on page 2-42for more
information.
2. Move the shift lever into P (Park) by pressing the
button on the shift lever and pushing the lever all
the way toward the front of the vehicle.
3. Turn the ignition key to LOCK/OFF.
4. Remove the key and take it with you. If you can
leave the vehicle with the key, the vehicle is in
P (Park).
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. 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.
If you have to leave the vehicle with the engine running,
be sure the vehicle is in P (Park) and the parking
brake is rmly set before you leave it. After you have
moved 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 pressing the
button on the console shift lever. If you can, it means
that the shift lever was not fully locked into P (Park).
2-43