Page 161 of 560

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 3‑30for
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 see Towing a Trailer
on page 5‑42for more
information.
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.
See Automatic Transmission Operation on page 3‑30.
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Page 162 of 560
Parking Brake
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. See
Brake System Warning Light
on
page 4‑32.
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 flash 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.
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Page 163 of 560

Shifting Into Park
{WARNING:
It can be dangerous to get out of the vehicle if the
shift lever is not fully in P (Park) with the parking
brake firmly 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 5‑42
.
1. Hold the brake pedal down, then set the parking brake.
2. Move the shift lever into the P (Park) position by pulling the shift lever toward you and moving it up
as far as it will go.
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 ignition key in your hand,
the vehicle is in P (Park).
Leaving the Vehicle With the Engine
Running
{WARNING:
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 firmly set. And, if you leave the
vehicle with the engine running, it could overheat
and even catch fire. 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 firmly set. After the shift lever is moved into P (Park),
hold the regular brake pedal down. Then, see if you can
move the shift lever away from P (Park) without first
pulling it toward you. If you can, it means that the shift
lever was not fully locked into P (Park).
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Page 164 of 560

Torque Lock
If you are parking on a hill and you do not shift the
transmission into P (Park) properly, the weight of the
vehicle can put too much force on the parking pawl in
the transmission. It might be difficult to pull the shift
lever out of P (Park). This is called torque lock.
To prevent torque lock, set the parking brake and then
shift into P (Park) properly before you leave the driver
seat. To find out how, seeShifting Into Park
on
page 3‑37.
When you are ready to drive, move the shift lever out
of P (Park) before releasing the parking brake.
If torque lock does occur, you might need to have
another vehicle push yours a little uphill to take some of
the pressure from the parking pawl in the transmission.
Then you should be able to pull the shift lever out of
P (Park).
Shifting Out of Park
This vehicle is equipped with an electronic shift lock
release system. The shift lock release is designed to:
.Prevent ignition key removal unless the shift lever
is in P (Park) with the shift lever button fully
released, and
.Prevent movement of the shift lever out of
P (Park), unless the ignition is in ON/RUN or
ACC/ACCESSORY and the regular brake pedal
is applied.
The shift lock release is always functional except in the
case of an uncharged or low voltage (less than 9 volt)
battery.
If the vehicle has an uncharged battery or a battery with
low voltage, try charging or jump starting the battery.
See Jump Starting
on page 6‑42for more information.
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Page 165 of 560
To shift out of P (Park) use the following:1. Apply the brake pedal.
2. Move the shift lever to the desired position.
If you still are unable to shift out of P (Park): 1. Ease the pressure on the shift lever.
2. While holding down the brake pedal, press the shift lever all the way into P (Park).
3. Move the shift lever to the desired position.
If you are still having a problem shifting, then have the
vehicle serviced soon.Parking Over Things That Burn
{WARNING:
Things that can burn could touch hot exhaust
parts under the vehicle and ignite. Do not park
over papers, leaves, dry grass, or other things that
can burn.
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Page 166 of 560

Engine Exhaust
{WARNING:
Engine exhaust contains Carbon Monoxide (CO)
which cannot be seen or smelled. Exposure to CO
can cause unconsciousness and even death.
Exhaust may enter the vehicle if:
.The vehicle idles in areas with poor ventilation
(parking garages, tunnels, deep snow that
may block underbody airflow or tail pipes).
.The exhaust smells or sounds strange or
different.
.The exhaust system leaks due to corrosion or
damage.
.The vehicle’s exhaust system has been
modified, damaged or improperly repaired.
.There are holes or openings in the vehicle
body from damage or after-market
modifications that are not completely sealed.(Continued)
WARNING: (Continued)
If unusual fumes are detected or if it is suspected
that exhaust is coming into the vehicle:
.Drive it only with the windows
completely down.
.Have the vehicle repaired immediately.
Never park the vehicle with the engine running in
an enclosed area such as a garage or a building
that has no fresh air ventilation.
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Page 167 of 560

Running the Vehicle While Parked
It is better not to park with the engine running. But if you
ever have to, here are some things to know.
{WARNING:
Idling a vehicle in an enclosed area with poor
ventilation is dangerous. Engine exhaust may
enter the vehicle. Engine exhaust contains
Carbon Monoxide (CO) which cannot be seen or
smelled. It can cause unconsciousness and
even death. Never run the engine in an enclosed
area that has no fresh air ventilation. For more
information, seeEngine Exhaust on page 3‑40.
{WARNING:
It can be dangerous to get out of the vehicle if the
automatic transmission shift lever is not fully in
P (Park) with the parking brake firmly 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).
Follow the proper steps to be sure the vehicle will not
move. See Shifting Into Park on page 3‑37.
If parking on a hill and pulling a trailer, see Towing a
Trailer on page 5‑42.
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Page 168 of 560

Mirrors
Manual Rearview Mirror
Hold the inside rearview mirror in the center to move it
for a clearer view behind your vehicle. Adjust the mirror
to avoid glare from the headlamps behind you. Push the
tab forward for daytime use and pull it for nighttime use.
Automatic Dimming Rearview Mirror
The vehicle may have an automatic dimming rearview
mirror.
Vehicles with OnStar
®have three additional control
buttons for the OnStar®system. See your dealer/retailer
for more information about OnStar®and how to
subscribe to it. See the OnStar®owner's guide for more
information about the services OnStar®provides.
O(On/Off): Press to turn the dimming feature on or off.
The vehicle may also have a Rear Vision Camera
(RVC). See Rear Vision Camera (RVC)
on page 3‑50for more information.
If the vehicle has RVC, the
O(On/Off) button for
turning the automatic dimming feature on or off will not
be available.
Automatic Dimming Mirror Operation
Automatic dimming reduces the glare from the
headlamps of the vehicle behind you. The dimming
feature comes on and the indicator light illuminates
each time the ignition is turned to start.
Cleaning the Mirror
Do not spray glass cleaner directly on the mirror. Use a
soft towel dampened with water.
3-42