Black plate (35,1)
GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating
9-35
Automatic
Transmission
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
Vehicles with an automatic
transmission have an electronic
shift position indicator within the
instrument panel cluster. This
display comes on when the ignition
key is turned to the ON/RUN
position.
There are several different positions
for the shift lever.
Hydra-Matic
®
4-Speed Automatic
Transmission
Heavy Duty 6-Speed Automatic
Transmission Shown (Light Duty
6
‐
Speed Similar)
See
“
Range Selection Mode
”
under
Manual Mode on page 9
‑
38
.
P (Park):
This position locks the
rear wheels. It is the best position
to use when starting the engine
because the vehicle cannot move
easily. When parked on a hill,
especially when the vehicle has a
heavy load, you might notice an
increase in the effort to shift out of
P (Park). See
“
Torque Lock
”
under
Shifting Into Park on page 9
‑
30
for
more information.
{
WARNING
It is 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.
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).
See
Shifting Into Park on
page 9
‑
30
. If you are pulling a
trailer, see
Driving Characteristics
and Towing Tips on page 9
‑
74
.
