GMC 2003 Sierra - Manual (Page 127)

If Itie 4HI. AUTO 4WO or 2HI swftch is pressed when
your vehicle is in gear and/or moving, Ihe 4HI,
AUTO 4WD or £HI indicalor ligh! will flash fgr
30 seconds but will not cornpKiele the shift unless j^our
vehicle is movir^g less Iban 3 mph (4.3 km/h) and
the transmission Is in NEUTRAl. [N).
Shifting into NEUTRAL
To shift the transfer case to NEUTRAL do the foltowing:
1. Make sure Itie vshicle Is parked sO that it will
not roll.
2. Set the parking brake.
3. Start Uie vehicle or torn the ignition to RUN
4. Conned the vehicle to the lowing vehicle.
5. Put the transmission In NEUTRAL (N)-.
6. Shift Ihe transfer case to 2HL
7. Simullaneously press and hofd the £HI and 4LO
bultons for 10 saoonds. The red NEUTRAL light
will come on when the transfer case shift To
NEUTRAL Is compIgtflK
B. Sfiitt Ibe transmissibn to REVERSE {R) for one
second, then shift The transmission to DRIVE (D)
for one secDnd.
9. Turn Ihe Ignilion to OFF.
10. Place Ihe trartsmlssion shtfi lever In PARK (P).
11. Hetease ihe parking brake prior to towing.
To shift 0 U 1 of NEUTRAL:
1. Set the parking brake and apply tha r^ular brake
pedal.
2. Shift the transmission to NEUTRAL (N) and turn the
ignilion to RUN with the engine oli.
3. Press the butlon for ftie de&iried transfer case shift
position (2HL 4ML AUTO 4WD or 4LO).
4. After Ihe transfer case has shifted out ot NEUTRAL
the red light will go out.
5. You may slari the engine and shift the transmission
10 Ihe destred position
Excessively shifting the transfer case Into or out of the
different mod os imay causa the transfe r casa io
enier Ihe shift protection mode. This wilt protect the
transfer case Irom possible damage and will only allow
the transfer case to respofid (0 one Shift per 10
seconds. The transfer Case may stay fn Ulte mode for
up te three minutes-
Shifting Out of NEUTRAL