2007 Chevrolet Silverado 1500 Pickup Owner's Manual - Page 160

4 m (Four-Wheel Drive High): Use this setting when you need extra traction, such a on snowy or icy roads or in most off-road situations. This setting also engages your front axle to help drive the vehicle. This is the best setting to use when plowing snow. 4 n (Four-Wheel Drive Low): This setting also engages the front axle and delivers extra torque. You may never need Four-Wheel Drive Low. It sends maximum power to all four wheels. You might choose Four-Wheel Drive Low if you are driving off-road in deep sand, deep mud, deep snow, and while climbing or descending steep hills. When operating in Four-Wheel Drive Low, the gear ratio provides additional torque when compared to Four-Wheel Drive High. The transmission gear shift feel will be exaggerated. If the SERVICE 4WD message stays on the Driver Information Center (DIC), you should take your vehicle to your dealer for service. See DIC Warnings and Messages on page 267 for further information. Shifting into Four-Wheel Drive High or AUTO 4WD (Automatic Four-Wheel Drive) Press and release the Four-Wheel Drive High or AUTO 4WD switch. This can be done at any speed, except when shifting from Four-Wheel Drive Low. The indicator light will flash while shifting. It will remain on when the shift is completed. Shifting into Two-Wheel Drive High Press and release the Two-Wheel Drive High switch. This can be done at any speed, except when shifting from Four-Wheel Drive Low. See shifting out of Four-Wheel Drive Low later in this section for more information. 160