Page 129 of 586

Automatic Transmission Operation
If the vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
The vehicle has a Hydra-Matic
®6L80 automatic
transmission, and has an electronic shift position
indicator within the instrument panel cluster. The
electronic shift position indicator displays when the shift
lever is moved out of P (Park).
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 you start 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 2-36for 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 2-36. If you are pulling a trailer, see
Towing a Trailer on page 5-42.
2-29
Page 130 of 586

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.
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 5-30.
N (Neutral):In this position, the engine does not
connect with the wheels. To restart when you are
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 under
Loss of Control on page 5-12.
2-30
Page 131 of 586

M (Manual Mode):This position lets drivers select
the range of gears appropriate for current driving
conditions. 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.
The vehicle has a shift stabilization feature that adjusts
the transmission shifting to the current driving
conditions in order to reduce rapid upshifts and
downshifts. This shift stabilization feature is designed to
determine, before making an upshift, if the engine
will be able to maintain vehicle speed by analyzing
things such as vehicle speed, throttle position and
vehicle load. If the shift stabilization feature determines
that a current vehicle speed cannot be maintained,
the transmission does not upshift and instead holds the
current gear. In some cases, this may appear to be
a delayed shift, however the transmission is operating
normally.The vehicle’s transmission uses adaptive shift controls
that compares key shift parameters to pre-programmed
ideal shifts stored in the transmissions computer.
The transmission constantly makes adjustments to
improve vehicle performance according to how
the vehicle is being used, such as with a heavy load or
when temperature changes. During this adaptive
shift controls process, shifting may feel different as the
transmission determines the best settings.
When temperatures are very cold, the Hydra-Matic
®
6L80 automatic transmission’s gear shifting may
be delayed providing more stable shifts until the engine
warms up. Shifts may be more noticeable with a cold
transmission. This difference in shifting is normal.
2-31
Page 132 of 586

Driver Shift Control (DSC)
The vehicle has Driver Shift Control (DSC). DSC
controls the vehicle’s 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, do the following:
1. Move the shift lever to the M (Manual Mode).
2. Press the plus/minus button, to upshift or downshift
selecting the desired range of gears for current
driving conditions.The DIC display will show the message MANUAL
SHIFT on the rst line and the current gear will be
displayed on the second line. SeeDriver Information
Center (DIC) on page 3-46andDIC Operation and
Displays on page 3-46for more information. The number
displayed in the DIC is the highest gear that can be
used. However, the vehicle can automatically shift
to lower gears as it adjusts to driving conditions. This
means that all gears below that number are available.
When 5 (Fifth ) is selected, 1 (First) through 5 (Fifth)
gears are automatically shifted by the vehicle, but
6 (Sixth) cannot be used until the plus/minus button
located on the steering column lever is used to change
to the gear.
Grade Braking is not available when the Driver Shift
Control is active. SeeTow/Haul Mode on page 2-33for
more information.
While using the DSC, cruise control and the tow/haul
mode can be used.
2-32
Page 133 of 586

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 when towing or hauling
heavy loads.
Press the button located on the end of the shift lever to
turn the tow/haul on or off. When the tow/haul is on,
a light on the instrument panel cluster will come on.
SeeTow/Haul Mode Light on page 3-45for more
information.
Also see “Tow Haul Mode” underTowing a Trailer on
page 5-42for more information.The tow/haul mode works with the Autoride
®feature,
if the vehicle has this, to enhance the ride when
trailering or with a loaded vehicle. SeeAutoride
®on
page 5-42.
Grade Braking
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 and
Automatic Transmission Operation on page 2-29for
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 vehicle is on
a downhill grade and the driver desires to slow the
vehicle by pressing the brake.
Also seeTowing a Trailer on page 5-42for more
information.
2-33
Page 134 of 586

Cruise Grade Braking
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.
Cruise Grade Braking operates while Cruise Control is
engaged in Tow/Haul mode to assist in maintaining
vehicle speed under loaded vehicle conditions. It utilizes
vehicle acceleration and deviation from desired speed
to determine the correct gear for the operating condition.
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 2-29.
Parking Brake
For vehicles with a release handle, set the parking
brake by holding the regular brake pedal down, then
pushing down the parking brake pedal.
If the ignition is on, the brake system warning light will
come on. SeeBrake System Warning Light on page 3-37.
A chime sounds and the warning light ashes 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. Then pull the bottom edge of the lever with
the parking brake symbol, located above the parking
brake pedal.
2-34
Page 135 of 586

If the ignition is on when the parking brake is released,
the brake system warning light goes 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 5-42.
For vehicles without a release handle, set the parking
brake by holding the regular brake pedal down,
then pushing down the parking brake pedal.If the ignition is on, the brake system warning light will
come on. SeeBrake System Warning Light on page 3-37.
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.
To release the parking brake, hold the regular brake
pedal down, then push down momentarily on the parking
brake pedal until you feel the pedal release. Slowly
pull your foot up off the park brake pedal. If the parking
brake is not released when you begin to drive, the
brake system warning light will ash and a chime will
sound warning you that the parking brake is still on.
If you are towing a trailer and are parking on a hill, see
Towing a Trailer on page 5-42.
2-35
Page 136 of 586