GMC Sierra Denali 2017 Owner's Manual page 278

Shifting into 4 will turn Traction
Control and StabiliTrak off. See
Traction Control/Electronic Stability
Control 0 284.
4 (Four-Wheel Drive High) : Use
when extra traction is needed. The
front axle engages and helps when
driving on snowy or icy roads, when
off-roading, or when plowing snow.
The vehicle can be shifted from 2
to 4 while the vehicle is moving.
Shifting Into 4
Turn the knob to 4 at any speed
up to 121 km/h (75 mph), except
from 4 . The indicator light will flash
while shifting and will remain on the
selected setting.
Shifting Into 2
Turn the knob to 2 at any speed,
except when shifting from 4 .
Shifting Into 4
When 4 is engaged, vehicle speed
should be kept below 72 km/h
(45 mph).
1. The ignition must be in ON/
RUN and the vehicle must be
stopped or moving less than
5 km/h (3 mph) with the
transmission in N (Neutral). It is
best for the vehicle to be
moving 1.6 to 3.2 km/h
(1 to 2 mph).
2. Turn the knob to 4 . Wait for
the 4 indicator light to stop
flashing before shifting the
transmission into gear.
If the transmission is in gear and/or
moving more than 5 km/h (3 mph),
the 4 indicator light will flash for
30 seconds and not complete the
shift. After 30 seconds the transfer
case will shift to 4 . Turn the knob
to 4 to see the indicator. With the
vehicle moving less than 5 km/h
(3 mph), and the transmission in
N (Neutral), attempt the shift again.
Shifting Out of 4
1. To shift out of 4 the vehicle
must be stopped or moving
less than 5 km/h (3 mph) with
the transmission in N (Neutral)
Driving and Operating
and the ignition in ON/RUN.
It is best for the vehicle to be
moving 1.6 to 3.2 km/h
(1 to 2 mph).
2. Turn the knob to 4 or 2 .
Wait for the 4 or 2 indicator
light to stop flashing before
shifting the transmission
into gear.
If the transmission is in gear and/or
moving more than 5 km/h (3 mph),
the 4 or 2 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 in N (Neutral), attempt
the shift again.
Shifting Into N (Neutral)
To shift:
1. Park the vehicle on a level
surface.
2. Set the parking brake and
press and hold the brake
pedal. See Parking
Brake 0 282.
3. Start the vehicle or turn the
ignition to ON/RUN.
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