GMC 2010 Sierra Owner's Manual page 188

4 (Four-Wheel-Drive Low): This setting also engages
the front axle and delivers extra torque. You may never
need this setting. It sends maximum power to all four
wheels. You might choose Four-Wheel-Drive Low if you
are driving off-road in deep sand, deep mud, deep
snow, and while climbing or descending steep hills.
If the vehicle has StabiliTrak
Four-Wheel-Drive Low will turn Traction Control
®
and StabiliTrak off. See StabiliTrak
page 5 6.
WARNING:
Shifting the transfer case to N (Neutral) can cause
the vehicle to roll even if the transmission is in
P (Park). You or someone else could be seriously
injured. Be sure to set the parking brake before
placing the transfer case in N (Neutral). See
Parking Brake on page 3 54.
3-50
®
, shifting into
®
System on
N (Neutral): Shift the vehicle's transfer case to
N (Neutral) only when towing the vehicle. See
Recreational Vehicle Towing on page 5 49 or Towing
Your Vehicle on page 5 48 for more information.
If the SERVICE 4 Wheel Drive message stays on, you
should take the vehicle to your dealer for service. See
Service 4 Wheel Drive message under DIC Warnings
and Messages on page 4 66.
Shifting Into Four-Wheel-Drive High or
AUTO (Automatic Four-Wheel Drive)
Turn the knob to the Four-Wheel-Drive High or AUTO
position. This can be done at any speed, except when
shifting from Four-Wheel-Drive Low. The indicator light
will flash while shifting. It will remain on when the shift is
completed.
Shifting Into Two-Wheel-Drive High
Turn the knob to the Two-Wheel-Drive High position.
This can be done at any speed, except when shifting
from Four-Wheel-Drive Low. The indicator light will
flash while shifting. It will remain on when the shift is
completed.