GMC 2008 Envoy - Manual (Page 109)

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 firmly set.
If you have four-wheel drive, your vehicle will be
free to roll – even if your lever is in PARK (P) – if
your transfer case is in NEUTRAL. So be sure
the transfer case is in a drive gear – not
NEUTRAL. See Four-Wheel Drive on page 2-29.
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
your vehicle with the engine running unless
you have to.
If you have to leave your vehicle with the engine
running, be sure your vehicle is in PARK (P) and your
parking brake is firmly 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 first pressing
the button on the console shift lever. If you can, it
means that the shift lever was not fully locked into
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 find 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 find out how, see Shifting Into
PARK (P) on page 2-34.
When you are ready to drive, move the shift lever out of
PARK (P) 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 the
pressure from the parking pawl in the transmission,
so you can pull the shift lever out of PARK (P).
2-35