2007 GMC ACADIA Owner's Manual

Automatic Transmission Operation
Your vehicle has an electronic shift position
indicator within the instrument panel cluster.
When using the Electronic Range Select Mode a
number will display next to the L, indicating
the current gear that has been selected.
See Electronic Range Select mode in this section
for more information.
Your automatic transmission has a shift lever
located on the console between the seats.
PARK (P):This position locks your front wheels. It
is the best position to use when you start your
engine because your vehicle cannot move easily.{CAUTION:
It is dangerous to get out of your vehicle
if the shift lever is not fully in PARK (P)
with the parking brake rmly set. Your
vehicle can roll.
Do not leave your 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 your vehicle will not
move, even when you are on fairly level
ground, always set your parking brake
and move the shift lever to PARK (P). See
Shifting Into Park (P) on page 135.Ifyou
are pulling a trailer, seeTowing a Trailer
on page 371.
Make sure the shift lever is fully in PARK (P)
before starting the engine. Your vehicle has an
automatic transmission shift lock control system.
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You must fully apply your regular brake rst and
then press the shift lever button before you
can shift from PARK (P) when the ignition key is in
ON. If you cannot shift out of PARK (P), ease
pressure on the shift lever, then push the
shift lever all the way into PARK (P) as you
maintain brake application. Then press the shift
lever button and move the shift lever into another
gear. SeeShifting Out of Park (P) on page 137.
REVERSE (R):Use this gear to back up.
Notice:Shifting to REVERSE (R) while your
vehicle is moving forward could damage the
transmission. The repairs would not be covered
by your warranty. Shift to REVERSE (R) only
after your vehicle is stopped.
To rock your vehicle back and forth to get out of
snow, ice or sand without damaging your
transmission, seeIf Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow on page 360.
NEUTRAL (N):In this position, your engine does
not connect with the wheels. To restart when
you are already moving, use NEUTRAL (N) only.
Also, use NEUTRAL (N) when your vehicle is
being towed.
{CAUTION:
Shifting into a drive gear while your
engine is running at high speed is
dangerous. Unless your foot is rmly on
the brake pedal, your vehicle could move
very rapidly. You could lose control and
hit people or objects. Do not shift into a
drive gear while your engine is running at
high speed.
Notice:Shifting out of PARK (P) or
NEUTRAL (N) with the engine running at high
speed may damage the transmission. The
repairs would not be covered by your warranty.
Be sure the engine is not running at high
speed when shifting your vehicle.
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DRIVE (D):This position is for normal driving. It
provides the best fuel economy for your vehicle. If
you need more power for passing, and you are:
Going less than 35 mph (56 km/h), push
your accelerator pedal about halfway down.
Going about 35 mph (56 km/h) or more, push
the accelerator all the way down.
Notice:If your vehicle seems to accelerate
slowly or not shift gears when you go faster,
and you continue to drive your vehicle that
way, you could damage the transmission. Have
your vehicle serviced right away. You can
drive in LOW (L) when you are driving less than
35 mph (56 km/h) and DRIVE (D) for higher
speeds until then.
LOW (L):This position gives you access to gear
ranges. This provides more engine braking but
lower fuel economy than DRIVE (D). You can use
it on very steep hills, or in deep snow or mud.
Electronic Range Select Mode
Electronic Range Selector (ERS) mode allows you
to choose the top-gear limit of the vehicle’s
transmission and the vehicle’s speed while driving
down hill or towing a trailer.
To use this feature, do the following:
1. Move the shift lever to LOW (L).
2. Press the plus/minus
button located on the
shift lever, to
increase or decrease
the gear range
available based
upon your current
driving conditions
and needs.
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When you shift from DRIVE (D) to LOW (L), the
transmission will shift to a pre-determined
lower gear range. The highest gear available for
this pre-determined range is displayed next to
the L in the DIC. SeeDriver Information Center
(DIC) on page 232andDIC Operation and
Displays (With DIC Buttons) on page 233orDIC
Operation and Displays (Without DIC Buttons)
on page 239for more information. The number
displayed in the DIC is the highest gear that
the transmission will be allowed to operate in.
However, your vehicle can automatically shift to
lower gears as required by various driving
conditions. This means that all gears below that
number are available. For example, when
FOURTH (4) is shown next to the L, FIRST (1)
through FOURTH (4) gears are automatically
shifted by the vehicle. You cannot shift into
FIFTH (5) until the plus (+) button is used or you
shift back into DRIVE (D) mode.While in LOW (L), the transmission will prevent
shifting to a lower gear range if the engine speed
is too high for the gear range you are trying to
select. You have a brief period of time to slow the
vehicle speed. If vehicle speed is not reduced
within the timeframe allowed, the lower gear range
attempted will not be available. The highest
possible gear that is allowed for that engine speed
will display next to the L in the DIC. Try again
to slow the vehicle speed and press the minus (−)
button to the desired lower gear range.
Automatic Engine Grade braking is not available
when the ERS is active. It is available in
DRIVE (D) for both normal and Tow/Haul mode.
While using the ERS, cruise control and the
tow/haul mode can be used. SeeTow/Haul Mode
on page 133for more information.
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Tow/Haul Mode
Your vehicle may have a Tow/Haul mode.
The button to turn it on
or off is located on
instrument panel under
the climate controls.
Push the button to turn it on, push it again to
deactivate the system. You can use this feature to
assist when towing or hauling a heavy load.
When Tow/Haul is activated the Tow/Haul symbol
will come on the instrument panel cluster. See
Tow/Haul ModeunderTowing a Trailer on
page 371for more information.
Automatic Engine Grade Braking
Automatic Engine 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, throttle position,
and whether the brake pedal is being pressed,
and determines when to keep the current vehicle
speed or to slow down. The system will then
automatically command downshifts that reduces
the vehicle’s speed, until the brake pedal is
no longer being pressed. This indicates the desired
vehicle speed has been reached.
While in the Electronic Range Select (ERS) mode,
grade braking is deactivated, allowing the driver
to select a range and limiting the highest gear
available. Grade braking is available for normal
driving and in Tow/Haul mode.
SeeAutomatic Transmission Operation on
page 129.
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Parking Brake
To set the parking
brake, push down the
parking brake pedal
down with your left foot.
If the ignition is on, the brake system warning light
will come on. SeeBrake System Warning Light
on page 222.Notice:Driving with the parking brake on can
overheat the brake system and cause
premature wear or damage to brake system
parts. Verify 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 with your right foot. Push down
momentarily on the parking brake pedal with
your left foot until you feel the pedal release, then
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 be on 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,
seeTowing a Trailer on page 371.
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Shifting Into Park (P)
{CAUTION:
It can be dangerous to get out of your
vehicle if the shift lever is not fully in
PARK (P) with the parking brake rmly
set. Your vehicle can roll. If you have left
the engine running, the vehicle can move
suddenly. You or others could be injured.
To be sure your 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 371.1. Hold the brake pedal down with your right foot
and set the parking brake.
2. Move the shift lever into PARK (P) by holding
in the button on the shift lever and pushing
the shift lever all the way toward the front
of the vehicle.
3. Turn the ignition key to OFF.
4. Remove the key and take it with you. If you
can leave your vehicle with the ignition key in
your hand, your vehicle is in PARK (P).
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Leaving Your Vehicle With the Engine
Running
{CAUTION:
It can be dangerous to leave your vehicle
with the engine running. Your vehicle could
move suddenly if the shift lever is not fully
in PARK (P) 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 your vehicle with the engine
running.
If you have to leave your vehicle with the engine
running, be sure your vehicle is in PARK (P) and
your parking brake is rmly set before you leave it.
After you have moved the shift lever into PARK (P),
hold the regular brake pedal down. Then, see if you
can move the shift lever away from PARK (P)
without rst pushing the button.
If you can, it means that the shift lever was not
fully locked in PARK (P).
Torque Lock
If you are parking on a hill and you do not shift your
transmission into PARK (P) properly, the weight of
the vehicle may put too much force on the parking
pawl in the transmission. You may nd it difficult to
pull the shift lever out of PARK (P). This is called
“torque lock.” To prevent torque lock, set the
parking brake and then shift into PARK (P) properly
before you leave the driver’s seat. To nd out how,
seeShifting Into Park (P) on page 135.
When you are ready to drive, move the shift lever
out of PARK (P)beforeyou release the parking
brake.
If torque lock does occur, you may need to have
another vehicle push your vehicle a little uphill
to take some of the pressure from the parking pawl
in the transmission, then you will be able to pull
the shift lever out of PARK (P).
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