GMC 2012 Canyon Owner's Manual page 209

If you have four-wheel drive, the
vehicle will be free to roll
if the shift lever is in P (Park)
the transfer case is in Neutral. So,
be sure the transfer case is in a
drive gear, two-wheel high (2H) or
four-wheel high (4H) or
four-wheel low (4L)
in Neutral.
2. Move the shift lever into P (Park)
by pulling the 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 key, the vehicle is in
P (Park).
even
if
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
not
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 before
you leave it. After you have moved
the shift lever 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, the
shift lever was not fully locked into
P (Park).
If you are parking on a hill and you
do not shift the transmission into
P (Park) properly, the weight of the
vehicle may put too much force on
the parking pawl in the
transmission. You may find it 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, see Shifting
Into Park (Automatic Transmission)
in this section.
When you are ready to drive, move
the shift lever out of P (Park) before
you release the parking brake.
If torque lock does occur, you may
need to have another vehicle push
yours a little uphill to take some of