GMC Yukon 2012 Owner's Manual page 306

9-40 Driving and Operating
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
your 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.
The vehicle may have significant
engagement noise and bump when
shifting between Four-Wheel Drive
Low and Four-Wheel Drive High
ranges or from N (Neutral) while the
engine is 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. With the vehicle moving less
than 5 km/h (3 mph) and the
transmission is in N (Neutral),
attempt the shift again.
I n f o r ma t i o n P r o v i d e d b y :
Shifting into Neutral
To shift the transfer case to
N (Neutral) do the following:
1. Make sure the vehicle is parked
so that it will not roll.
2. Set the parking brake and apply
the regular brake pedal. See
Parking Brake on page 9 45 for
more information.
3. Start the vehicle or turn the
ignition to ON/RUN.
4. Put the transmission in
N (Neutral).
5. Shift the transfer case to
Two-Wheel Drive High.