GMC 2007 Acadia - Manual (Page 130)

You must fully apply your regular brake first 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. See Shifting 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, see If 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 firmly 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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