Black plate (45,1)
GMC 2015i Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
8431499) - 2015 - CRC - 6/20/14
Driving and Operating
9-45
knob may have been turned while
the vehicle was off. To see the
indicator, turn the knob to another
position so that it matches the
actual transfer case setting. If no
lights display, take the vehicle to
your dealer for service. An indicator
light flashes while shifting the
transfer case and remains
illuminated when the shift is
complete.
If the transfer case cannot make a
requested shift, it will return to the
last chosen setting. Turn the knob
back to the previous transfer case
setting to see the indicator.
The settings are:
N (Neutral):
Use only when the
vehicle needs to be towed. See
Recreational Vehicle Towing on
page 10-94
or
Towing the Vehicle
on page 10-94
.
2
m
(Two-Wheel Drive High):
Use
for driving on most streets and
highways. The front axle is not
engaged. This setting provides the
best fuel economy.
AUTO (Automatic Four-Wheel
Drive):
Use when road surface
traction conditions are variable.
When driving in AUTO, the front
axle is engaged, and the vehicle's
power is sent to the front and rear
wheels automatically based on
driving conditions. This setting
provides slightly lower fuel economy
than 2
m
.
Do not use AUTO mode to park on
a steep grade with poor traction
such as ice, snow, mud, or gravel.
In AUTO mode only the rear wheels
will hold the vehicle from sliding
when parked. If parking on a steep
grade, use 4
m
to keep all four
wheels engaged.
4
m
(Four-Wheel Drive High):
Use
this position when extra traction is
needed, such as when driving on
snowy or icy roads, when
off-roading, or when plowing snow.
4
n
(Four-Wheel Drive Low):
This
setting engages the front axle and
delivers extra torque. Choose 4
n
when driving off-road in deep sand,
deep mud, or deep snow, and while
climbing or descending steep hills.
Shifting into 4
n
will turn Traction
Control and StabiliTrak off. See
Traction Control/Electronic Stability
Control on page 9-50
.
Shifting Into 4
m
or AUTO
Turn the knob to the 4
m
or AUTO
position at any speed, except from
4
n
. The indicator light will flash
while shifting and will remain on
when the shift is completed.
Shifting Into 2
m
Turn the knob to 2
m
at any speed,
except when shifting from 4
n
. The
indicator light will flash while shifting
and will remain on when the shift is
completed.
