GMC 2007 Yukon XL Owner's Manual page 153

CAUTION: (Continued)
If you have four-wheel drive and your
transfer case is in NEUTRAL, your vehicle
will be free to roll, even if your shift lever
is in PARK (P). So be sure the transfer
case is in a drive gear — not in NEUTRAL.
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 the parking brake is firmly set before
you leave it. After you move 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 pulling it toward you.
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 152.
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, then you will be able to
pull the shift lever out of PARK (P).
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