GMC 2007 Yukon XL Owner's Manual page 150

Shifting into NEUTRAL
To shift the transfer case to NEUTRAL do the
following:
1. Make sure the vehicle is parked so that it will
not roll.
2. Set the parking brake. See Parking Brake on
page 151 for more information.
3. Start the vehicle or turn the ignition to RUN.
4. Put the transmission in NEUTRAL (N).
5. Shift the transfer case to Two-Wheel
Drive High.
6. Turn the transfer case knob to NEUTRAL and
hold it for 10 seconds. The NEUTRAL light
will come on when the transfer case shift
to NEUTRAL is complete.
7. If the engine is running, verify that the
transmission is in NEUTRAL (N) by shifting the
transmission to REVERSE (R) for one second,
then shift the transmission to DRIVE (D) for
one second.
8. Turn the ignition to ACCESSORY, which will
turn the engine off.
9. Place the transmission shift lever in PARK (P).
10. Turn the ignition to LOCK.
150
Shifting Out of NEUTRAL
To shift out of NEUTRAL do the following:
1. Set the parking brake and apply the regular
brake pedal.
2. Shift the transmission to NEUTRAL (N) and
turn the ignition to RUN with the engine off.
3. Turn the transfer case knob to the desired
transfer case shift position (Two-Wheel
Drive High, Four-Wheel Drive High, AUTO).
After the transfer case has shifted out of
NEUTRAL the NEUTRAL light will go out.
4. Release the parking brake.
Notice: Shifting the transmission into gear
before the Four-Wheel Low indicator light has
stopped flashing could damage the transfer
case. To help avoid damaging your vehicle,
always wait for the Four-Wheel Low indicator
light to stop flashing before shifting the
transmission into gear.
5. Start the engine and shift the transmission to
the desired position.
Excessively shifting the transfer case into or out of
the different modes may cause the transfer case to
enter the shift protection mode.