GMC 2006 Sierra 1500 Pickup Owner's Manual page 139

Shifting Out of Four-Wheel Low
To shift from Four-Wheel Low to Four-Wheel High,
AUTO 4WD, or Two-Wheel High, your vehicle must be
stopped or moving less than 3 mph (5 km/h) with the
transmission in NEUTRAL (N) and the ignition in RUN.
The preferred method for shifting out of Four-Wheel
Low is to have your vehicle moving 1 to 2 mph (1.6 to
3.2 km/h). Press and release the Four-Wheel High,
AUTO 4WD, or Two-Wheel High switch. You must wait
for the Four-Wheel High, AUTO 4WD, or Two-Wheel
High indicator light to stop flashing and remain on before
shifting your transmission into gear.
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.
The transfer case may make noise and the vehicle
may jerk when the transfer case is shifted between
Four-Wheel Low and Four-Wheel High ranges or
from NEUTRAL with the engine running.
If the four-wheel high, AUTO 4WD, or Two-Wheel High
switch is pressed when your vehicle is in gear and/or
moving, the Four-Wheel High, AUTO 4WD, or
Two-Wheel High indicator light will flash for 30 seconds
but will not complete the shift unless your vehicle is
moving less than 3 mph (5 km/h) and the transmission
is in NEUTRAL (N).
Shifting Into NEUTRAL
CAUTION:
{
Shifting the transfer case to NEUTRAL
can cause your vehicle to roll even if the
transmission is in PARK (P). You or someone
else could be seriously injured. Be sure to set
the parking brake before placing the transfer
case in NEUTRAL. See Parking Brake on
page 2-52.
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.
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 High.
6. Simultaneously press and hold the Two-Wheel High
and Four-Wheel Low buttons for 10 seconds. The
red NEUTRAL light will come on when the transfer
case shift to NEUTRAL is complete.
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