Chevrolet 2006 Avalanche Owner's Manual page 299

Q:
Suppose, after stalling, I try to back down the hill
and decide I just cannot do it. What should I do?
A:
Set the parking brake, put the transmission in
PARK (P) and turn off the engine. Leave the vehicle
and go get some help. Exit on the uphill side and
stay clear of the path the vehicle would take if it
rolled downhill. Do not shift the transfer case to
NEUTRAL when you leave the vehicle. Leave it in
some gear.
CAUTION:
{
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the
transmission is in PARK (P). This is because
the NEUTRAL position on the transfer case
overrides the transmission. You or someone
else could be injured. If you are going to leave
your vehicle, set the parking brake and shift
the transmission to PARK (P). But do not shift
the transfer case to NEUTRAL. Leave the
transfer case in the Two-Wheel High,
Four-Wheel High or Four-Wheel Low position.
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