2003 Hummer H2 Owner's Manual - Page 112

Shifting to 4HI or 4HI Lock With the vehicle traveling less than 40 mph (64 km/h), press and release the 4HI or 4HI Lock button. The indicator light will flash while shifting. It will remain illuminated when the shift is complete. Shifting to 4LO Lock To shift to 4LO Lock, the vehicle's engine must be running and the vehicle must be stopped or moving less than 2 mph (3.2 km/h) with the transmission in NEUTRAL (N). The preferred method for shifting into 4LO Lock is to have your vehicle moving 1 or 2 mph (1.6 to 3.2 km/h). Press and release the 4LO Lock button. You must wait for the 4LO Lock indicator light to stop flashing and remain illuminated before shifting your transmission into gear. If the 4LO Lock button is pressed when your vehicle is in gear and/or moving, the 4LO Lock indicator light will flash for 15 seconds and not complete the shift unless your vehicle is moving less than 2 mph (3.2 km/h) and the transmission is in NEUTRAL (N). After 30 seconds, the transfer case will return to the setting last chosen. Shifting Out of 4LO Lock To shift from 4LO Lock to 4HI or 4HI Lock your vehicle must be stopped or moving less than 2 mph (3.2 km/h) with the transmission in NEUTRAL (N) and the engine running. The preferred method for shifting out of 4LO Lock is to have your vehicle moving 1 or 2 mph (1.6 to 3.2 km/h). Press the 4HI or 4HI Lock button. You must wait for the 4HI or 4HI Lock indicator light to stop flashing and remain illuminated before shifting your transmission into gear. If the 4HI or 4HI Lock button is pressed when your vehicle is in gear and/or moving, the 4HI or 4HI Lock indicator light will flash for 15 seconds but will not complete the shift unless your vehicle is moving less than 2 mph (3.2 km/h) with the transmission in NEUTRAL (N). 2-30