2008 Hummer H3 Owner's Manual - Page 103

Indicator lights in the buttons show which mode you are in. The indicator lights will come on briefly when you turn on the ignition the mode the vehicle is in will stay on. If the lights do not come on, you should take your vehicle to your dealer for service. An indicator light will flash while shifting the transfer case. It will remain lit when the shift is complete. If for some reason 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, you should take your vehicle to your dealer for service. See Service 4WD message under DIC Warnings and Messages on page 3-43. 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 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). Press and release the Four-Wheel-Low Lock button. If your 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 Four-Wheel-Low Lock indicator light to stop flashing and remain lit before shifting your transmission in gear. It is normal for your vehicle to have engagement noise and bump when shifting between Four-Wheel Low and Four-Wheel High ranges or from NEUTRAL with the engine running. If the Four-Wheel-Low Lock button is pressed when your 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 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 last chosen setting. 2-29 Shifting between Four-Wheel High and Four-Wheel-High Lock With the vehicle traveling less than 45 mph (72 km/h), press and release the Four-Wheel High or Four-Wheel-High Lock button. The indicator light will flash while shifting. It will remain lit when the shift is complete. 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.