2009 Hummer H3T Owner's Manual - Page 91

Features and Controls An indicator light will flash while shifting the transfer case. If the transfer case cannot make a requested shift, it will return to the last chosen setting. If the SERV 4WD message on the Driver Information Center (DIC) stays on, take the vehicle to your dealer/retailer for service. See Service 4WD message under DIC Warnings and Messages on page 3-37. Shifting between Four-Wheel High and Four-Wheel-High Lock With the vehicle traveling less than 75 mph (120 km/h), press and release the Four-Wheel High or Four-Wheel-High Lock button. It may be necessary to drive backwards while turning for a distance of 25 feet (7.5 m) to get the lock feature to disengage. Shifting into Four-Wheel Low Lock 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. To shift into Four-Wheel-Low Lock, the ignition must be in ON/RUN and the vehicle must be stopped or moving less than 3 mph (5 km/h) with the transmission in N (Neutral). The preferred method for shifting into Four-Wheel Low is to have the vehicle moving 1 to 2 mph (1.6 to 3.2 km/h). Press and release the Four-Wheel-Low Lock button. If the vehicle has a manual transmission, the clutch pedal must be pressed to the floor while you press the Four-Wheel-Low Lock button, or the shift will not be completed. You must wait for the 2-25 Four-Wheel-Low Lock indicator light to stop flashing and remain lit before shifting the transmission into gear. It is normal for the vehicle to have engagement noise and bump when shifting between Four-Wheel Low and Four-Wheel High ranges or from Neutral. If the Four-Wheel-Low Lock button is pressed when the vehicle is in gear and/or moving too fast, the Four-Wheel-Low Lock indicator light will flash for 15 seconds and not complete the shift.