2004 Hummer H2 Owner's Manual - Page 107
2004 Hummer H2 Manual
Page 107 highlights
Shifting into 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. It may be necessary to drive backwards for a short distance of 25 feet (7.5 m) to get the lock feature to disengage. It is typical for your vehicle to exhibit significant engagement noise and bump when shifting between 4LO and 4HI ranges or from NEUTRAL with the engine running. 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 15 seconds the transfer case will return to the setting last chosen. Shifting into 4LO Lock To shift into 4LO Lock, the ignition must be in RUN 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 is to have your vehicle moving 1 to 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 in gear. Notice: Shifting the transmission into gear before the indicator light stops flashing could cause damage to the transfer case. Always wait until the indicator lights stops flashing before putting the transmission back in gear. 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 ignition in RUN. The preferred method for shifting out of 4LO Lock is to have your vehicle moving 1 to 2 mph (1.6 to 3.2 km/h). Press and release 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. It is typical for your vehicle to exhibit significant engagement noise and bump when shifting between 4LO and 4HI ranges or from NEUTRAL with the engine running. 2-27