2010 Hummer H3 Owner's Manual - Page 231

Driving and Operating Notice: Operating the vehicle in Four-Wheel-Low Lock above 48 km/h (30 mph) for any extended period of time could cause damage to the transfer case. Do not operate the vehicle in Four-Wheel-Low Lock above 48 km/h (30 mph) for extended periods. 4 n Q (Four-Wheel-Low Lock): This setting delivers extra torque to all four wheels and is used for extreme off-road conditions. If the vehicle has locking axles, they can be locked for additional traction in extreme off-road situations. See Locking Rear Axle on page 9‑54 and Locking Front Axle on page 9‑55. Indicator lights in the buttons show which setting the transfer case is in. The indicator lights will come on briefly when the ignition is in ON/RUN. The If the lights do not come on, take the vehicle to your dealer for service. 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 for service. See Service 4WD message under Driver Information Center (DIC) on page 5‑18. Shifting between Four-Wheel High and Four-Wheel-High Lock With the vehicle traveling less than 120 km/h (75 mph), 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 7.5 m (25 feet) 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. 9-47 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 5 km/h (3 mph) with the transmission in N (Neutral). The preferred method for shifting into Four-Wheel Low is to have the vehicle moving 1.6 to 3.2 km/h (1 to 2 mph). 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 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.