Notice:Using a tool to force the key to turn in the
ignition could cause damage to the switch or break
the key. Use the correct key, make sure it is all the
way in, and turn it only with your hand. If the key
cannot be turned by hand, see your dealer/retailer.
B (ACC/ACCESSORY):This position lets things like the
radio and the windshield wipers operate while the
engine is off. Use this position if the vehicle must be
pushed or towed.
C (ON/RUN):This position can be used to operate the
electrical accessories and to display some instrument
panel cluster warning and indicator lights. The
switch stays in this position when the engine is running.
The transmission is also unlocked in this position on
automatic transmission vehicles.
If you leave the key in the ACC/ACCESSORY or
ON/RUN position with the engine off, the battery could
be drained. You may not be able to start the vehicle
if the battery is allowed to drain for an extended period
of time.
D (START):This is the position that starts the engine.
When the engine starts, release the key. The ignition
switch returns to ON/RUN for driving.
A warning tone will sound when the driver door is
opened, the ignition is in ACC/ACCESSORY or
LOCK/OFF and the key is in the ignition.Retained Accessory Power (RAP)
The following vehicle accessories can be used for up to
10 minutes after the engine is turned off:
Audio System
Power Windows
OnStar®System (if equipped)
Sunroof (if equipped)
These features work when the key is in ON/RUN or
ACC/ACCESSORY. Once the key is turned from
ON/RUN to LOCK/OFF, the windows and sunroof
continue to work up to 10 minutes until any door
is opened. The radio continues to work for up to
10 minutes or until the driver door is opened.
Starting the Engine
Move the shift lever to P (Park) or N (Neutral). The
engine will not start in any other position. To restart the
engine when the vehicle is already moving, use
N (Neutral) only.
Notice:Do not try to shift to P (Park) if the vehicle
is moving. If you do, you could damage the
transmission. Shift to P (Park) only when the vehicle
is stopped.
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Starting Procedure
1. With your foot off the accelerator pedal, turn the
ignition to START. When the engine starts, let go
of the key. The idle speed will slow down as
the engine warms. Do not race the engine
immediately after starting it. Operate the engine and
transmission gently to allow the oil to warm up
and lubricate all moving parts.
The vehicle has a Computer-Controlled Cranking
System. This feature assists in starting the engine
and protects components. If the ignition key is turned
to the START position, and then released when the
engine begins cranking, the engine will continue
cranking for a few seconds or until the vehicle starts.
If the engine does not start and the key is held in
START, cranking will be stopped after 15 seconds to
prevent cranking motor damage. To prevent gear
damage, this system also prevents cranking if the
engine is already running. Engine cranking can be
stopped by turning the ignition switch to the ACC/
ACCESSORY or LOCK/OFF position.
Notice:Cranking the engine for long periods of
time, by returning the key to the START position
immediately after cranking has ended, can overheat
and damage the cranking motor, and drain the
battery. Wait at least 15 seconds between each try,
to let the cranking motor cool down.2. If the engine does not start after 5-10 seconds,
especially in very cold weather (below 0°F or
−18°C), it could be ooded with too much gasoline.
Try pushing the accelerator pedal all the way to
the oor and holding it there as you hold the key in
START for up to a maximum of 15 seconds.
Wait at least 15 seconds between each try, to allow
the cranking motor to cool down. When the
engine starts, let go of the key and accelerator. If
the vehicle starts brie y but then stops again, repeat
these steps. This clears the extra gasoline from
the engine. Do not race the engine immediately
after starting it. Operate the engine and
transmission gently until the oil warms up and
lubricates all moving parts.
Notice:The engine is designed to work with the
electronics in the vehicle. If you add electrical parts
or accessories, you could change the way the
engine operates. Before adding electrical equipment,
check with your dealer/retailer. If you do not, the
engine might not perform properly. Any resulting
damage would not be covered by the vehicle
warranty.
2-33
Adjustable Throttle and Brake Pedal
The vehicle has adjustable throttle and brake pedals
that allow you change their positions.
The feature will not operate when the vehicle is in
R (Reverse) or while using the cruise control.
The switch used to adjust the pedals is located on the
center console below the climate control system.
Press the right and left arrows to move the pedals either
closer or further from your body.Before you start driving, fully press the brake pedal to
con rm the adjustment is right for you. While driving,
make only small adjustments.
The vehicle has a memory function which allows the
pedal positions to be saved and recalled. SeeMemory
Features on page 1-7for more information.
Engine Coolant Heater
The engine coolant heater can provide easier starting
and better fuel economy during engine warm-up in cold
weather conditions at or below 0°F (−18°C). Vehicles
with an engine heater should be plugged in at least
four hours before starting. An internal thermostat in the
plug-end of the cord may exist which will prevent
engine coolant heater operation at temperatures above
0°F (−18°C).
2-34
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord. The
cord is located on the driver’s side of the engine
compartment, near the power steering uid
reservoir.
3. Plug the cord into a normal, grounded 110-volt AC
outlet.{CAUTION:
Plugging the cord into an ungrounded outlet could
cause an electrical shock. Also, the wrong kind of
extension cord could overheat and cause a re.
You could be seriously injured. Plug the cord into
a properly grounded three-prong 110-volt AC
outlet. If the cord will not reach, use a heavy-duty
three-prong extension cord rated for at least
15 amps.
4. Before starting the engine, be sure to unplug and
store the cord as it was before to keep it away
from moving engine parts. If you do not, it could be
damaged.
The length of time the heater should remain plugged in
depends on several factors. Ask a dealer/retailer in
the area where you will be parking the vehicle for the
best advice on this.
2-35
Automatic Transmission Operation
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 2-43for 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 5-40.
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.
2-36
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 5-29.
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 5-11.
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.
2-37
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.
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.
2-38
Also see “Tow Haul Mode” underTowing a Trailer on
page 5-40for 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 5-39.
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 2-36for
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 5-40for 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.
SeeAutomatic Transmission Operation on page 2-36.
2-40