GMC Envoy Owner's Manual page 102

Shifting Out of 4LO
To shift from 4LO to 4HI, A4WD or 2HI your vehicle must
be stopped or moving less than 2 mph (3.2 km/h) with the
transmission in NEUTRAL (N) and the engine running.
The preferred method for shifting out of 4LO is to have
your vehicle moving 1 or 2 mph (1.6 to 3.2 km/h). Turn
the knob to 4HI, A4WD or 2HI. You must wait for the 4HI,
A4WD or 2HI indicator light to stop flashing and remain
illuminated before shifting your transmission into gear.
If the knob is turned to 4HI, A4WD or 2HI when your
vehicle is in gear and/or moving, the 4HI, A4WD or 2HI
indicator light will flash for 30 seconds. It will not complete
the shift unless your vehicle is moving less than 2 mph
(3.2 km/h) with the transmission in NEUTRAL (N).
Shifting into NEUTRAL
Before shifting the transfer case to NEUTRAL, first
make sure the vehicle is parked so that it will not roll.
1. Set the parking brake.
2. Start the vehicle.
3. Put the transmission in NEUTRAL (N).
4. Turn the transfer case knob all of the way past 4LO
and hold it there for a minimum of 10 seconds. The
neutral indicator light will come on.
5. Shift the transmission to REVERSE (R) for
one second, then shift the transmission to
DRIVE (D) for one second.
6. Place the transmission shift lever in PARK (P).
7. Turn the ignition to LOCK.
8. For info on towing your vehicle see Recreational
Vehicle Towing on page 4-51.
Shifting Out of NEUTRAL
To shift the transfer case out of NEUTRAL,
do the following:
1. Set the parking brake and apply the regular
brake pedal.
2. Start the vehicle with the transmission in PARK (P).
3. Turn the transfer case knob to the desired shift
position (2HI, 4HI or A4WD).
4. Put the transmission in NEUTRAL (N).
5. Release the parking brake.
6. After the transfer case has shifted out of NEUTRAL,
the indicator light will go out. Shift the transmission
lever to the desired position.
A re-engagement sound is normal when shifting
out of NEUTRAL.
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