GMC YUKON DENALI 2000 Manual page 201

Here are some things you must not do if you stall, or are
about to stall, when going up a hill.
D
Never attempt to prevent a stall by shifting into
NEUTRAL (N) to "rev
forward momentum. This won't work. Your vehicle
will roll backwards very quickly and you could go
out of control.
Instead, apply the regular brake to stop the
vehicle. Then apply the parking brake. Shift to
REVERSE (R), release the parking brake, and
slowly back straight down.
D
Never attempt to turn around if you are about to
stall when going up a hill. If the hill is steep enough
to stall your vehicle, it's steep enough to cause you
to roll over if you turn around. If you can't make it
up the hill, you must back straight down the hill.
Q:
Suppose, after stalling, I try to back down the
hill and decide I just can't do it. What should
I do?
A:
Set the parking brake, put your transmission in
PARK (P) and turn off the engine. Leave the
vehicle and go get some help. Exit on the uphill
-
up" the engine and regain
side and stay clear of the path the vehicle would
take if it rolled downhill. Do not shift the transfer
case to NEUTRAL (N) when you leave the vehicle.
Leave it in some gear.
CAUTION:
Shifting the transfer case to NEUTRAL (N) can
cause your vehicle to roll even if the transmission
is in PARK (P) (or, if you have the manual
transmission, even if you're in gear). This is
because the NEUTRAL (N) 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) (or, put your
manual transmission in FIRST (1)). But do not
shift the transfer case to the NEUTRAL (N)
position. Leave the transfer case in the 2 Wheel
High, 4 High or 4 Low position.
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