GMC 2012 Sierra - Manual (Page 327)

Black plate (51,1) GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-51
Notice: Shifting the transmission
into gear before the requested
mode indicator light has stopped
flashing could damage the
transfer case. To help avoid
damaging the vehicle, always wait
for the mode indicator lights to
stop flashing before shifting the
transmission into gear.
It is typical for the vehicle to exhibit
significant engagement noise and
bump when shifting between
Four-Wheel Drive Low and
Four-Wheel Drive High ranges or
from N (Neutral) with the engine
running.
If the knob is turned to the
Four-Wheel Drive Low position
when the vehicle is in gear and/or
moving more than 5 km/h (3 mph),
the Four-Wheel Drive Low indicator
light will flash for 30 seconds
and not complete the shift. After
30 seconds the transfer case
will shift to Four-Wheel Drive
High mode.
Shifting Out of Four-Wheel
Drive Low
To shift from Four-Wheel Drive Low
to Four-Wheel Drive High, AUTO or
Two-Wheel Drive High, the vehicle
must be stopped or moving less
than 5 km/h (3 mph) with the
transmission in N (Neutral) and
the ignition in ON/RUN. The
preferred method for shifting
out of Four-Wheel Drive Low
is to have the vehicle moving
1.6 to 3.2 km/h (1 to 2 mph). Turn the
knob to the Four-Wheel Drive High,
AUTO or Two-Wheel Drive High
position. You must wait for the
Four-Wheel Drive High, AUTO or
Two-Wheel Drive High indicator light
to stop flashing and remain on
before shifting the transmission
into gear.
Notice: Shifting the transmission
into gear before the requested
mode indicator light has stopped
flashing could damage the
transfer case. To help avoid
damaging the vehicle, always wait
for the mode indicator lights to
stop flashing before shifting the
transmission into gear.
It is typical for the vehicle to exhibit
significant engagement noise
and bump when shifting between
Four-Wheel Drive Low and
Four-Wheel Drive High ranges or
from N (Neutral) with the engine
running.
If the knob is turned to the
Four-Wheel Drive High, AUTO,
or Two-Wheel Drive High switch
position when the vehicle is
in gear and/or moving more than
5 km/h (3 mph), the Four-Wheel
Drive High, AUTO or Two-Wheel
Drive High indicator light will flash
for 30 seconds but will not complete
the shift.