2008 Hummer H2 Owner's Manual - Page 120

Shifting between Four-Wheel High and Four-Wheel-High Lock With the vehicle traveling less than 40 mph (64 km/h), turn the dial to the Four-Wheel High or Four-Wheel-High Lock position. The indicator light on the dial will flash while shifting. It will remain on when the shift is complete. It may be necessary to drive backwards for a short distance of 25 feet (7.5 m) to get the lock feature to disengage. When the transfer case is shifted into Four-Wheel-Low Lock position a StabiliTrak® indicator light will come on to show that the system has been turned off and a message will show in the DIC. See DIC Warnings and Messages on page 3-56 for more information. Notice: Shifting the transmission into gear before the indicator light stops flashing could cause damage to the transfer case. Always wait until the indicator light stops flashing before putting the transmission back in gear. It is normal for your vehicle to have engagement noise and bump when shifting between Four-Wheel Low and Four-Wheel High or Four-Wheel-High Lock ranges or from NEUTRAL with the engine running. If the Four-Wheel-Low Lock position is selected when your vehicle is in gear and/or moving, the Four-Wheel Low Lock indicator light will flash for 15 seconds and not complete the shift unless your vehicle is moving less than 3 mph (5 km/h) and the transmission is in NEUTRAL (N). After 15 seconds the transfer case will return to the setting last chosen. Shifting into Four-Wheel-Low Lock To shift into Four-Wheel-Low Lock, the ignition must be in RUN and the vehicle must be stopped or moving less than 3 mph (5 km/h) with the transmission in NEUTRAL (N). The preferred method for shifting into Four-Wheel Low is to have your vehicle moving 1 to 2 mph (1.6 to 3.2 km/h). Turn the dial to the Four-Wheel-Low Lock position. You must wait for the Four-Wheel-Low Lock indicator light on the dial to stop flashing and remain lit before shifting the transmission in gear. 2-38