GMC Sierra 2014 Owner's Manual page 310

9-46 Driving and Operating
Shifting Out of Four-Wheel
Drive Low
To shift from Four-Wheel Drive Low
to Four-Wheel Drive High 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 or
Two-Wheel Drive High position. You
must wait for the Four-Wheel Drive
High or Two-Wheel Drive High
indicator light to stop flashing before
shifting the transmission into gear.
Caution
Shifting the transmission into
gear before the requested mode
indicator light has stopped
flashing could damage the
Caution (Continued)
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 transfer case N (Neutral) with
the engine running.
If the knob is turned to the
Four-Wheel Drive High 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 or Two-Wheel Drive High
indicator light will flash for
30 seconds, but will not complete
the shift. With the vehicle moving
(Continued)
less than 5 km/h (3 mph), and the
transmission in N (Neutral), attempt
the shift again.
Shifting into N (Neutral)
To shift the transfer case to
N (Neutral):
1. Make sure the vehicle is parked
so that it will not roll.
2. Set the parking brake and press
and hold the regular brake
pedal. See Parking Brake on
page 9-53.
3. Start the vehicle or turn the
ignition to ON/RUN.
4. Shift the transmission to
N (Neutral).
5. Shift the transfer case to
Two-Wheel Drive High.
6. Turn the transfer case dial
clockwise to N (Neutral) until it
stops and hold it there until the
N (Neutral) light starts blinking.
This will take at least
10 seconds. Then slowly release
the dial to the Four-Wheel Drive