1997 GMC Suburban Owner's Manual - Page 97

Electronic Transfer Case (If Equipped) 4HI: This setting engages your front axle to help drive your vehicle. Use 4HI when you need extra traction, such as on snowy or icy roads, or in most off-road situations. 4LO: This setting alsoengages your front axle to give you extra traction. You may never need 4LO. It sends the maximum power to all four wheels. You might choose 4LO if you were driving off-road in sand, mud or deep snow and climbing or descending steep hills. Indicator lights in the switches show you which setting you are in. The indicator lights will come on briefly when you turn on the ignition and the last chosen setting If your four-wheel-drive vehicle has the electronic transfer case,the transfer case switches arebelow and to the left of the climate controls. Use these switches to shift intoand out of four-wheel drive. You can choose among three driving settings: shift is completed. If for some reason the transfer case cannot make a requested shift, it will return to the last chosen setting. 2HI: This setting is for driving in most street and highway situations. Your front axle is not engaged in two-wheel drive. Shifting from 2HI to 4HI Press and releasethe 4HI switch. This canbe done at any speed, and the indicator light will flash while shifting.It will remain illuminated when the shift is completed. 2-23