GMC 2015 Sierra Denali Owner's Manual page 222

8. Turn the engine off, and the
ignition to ACC/ACCESSORY.
9. Place the transmission shift
lever in P (Park).
10. See Recreational Vehicle
Towing on page 10-91.
11. Turn the ignition to LOCK/OFF.
Shifting Out of N (Neutral)
To shift out of N (Neutral):
1. Set the parking brake and apply
the brake pedal.
2. Turn the ignition to ON/RUN with
the engine off.
3. Shift the transmission to
N (Neutral).
4. Turn the transfer case knob to
2 .
After the transfer case has
shifted out of N (Neutral), the
N (Neutral) light will go out.
5. Release the parking brake.
Caution
Shifting the transmission into gear
before the requested mode
indicator light has stopped
flashing could damage the
transfer case.
6. Start the engine and shift the
transmission to the desired gear.
Automatic Transfer Case
Driving and Operating
Use the transfer case knob next to
the steering wheel to shift into and
out of four-wheel drive.
Indicator lights display which setting
the transfer case is in. N (Neutral) is
indicated on the face of the knob.
The indicator lights will display
briefly when the ignition is turned on
and one will stay on. If the lights
display momentarily when the
ignition is in ON/RUN, but none stay
on, the 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.
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