See also:

Shifting Into Four-Wheel Drive High or AUTO (Automatic Four-Wheel Drive)
Turn the knob to the Four-Wheel Drive High or AUTO position. This can be done at any speed, except when shifting from Four-Wheel Drive Low. The indicator light will flash while shifting. It will remai ...

After Off-Road Driving
Remove any brush or debris that has collected on the underbody or chassis, or under the hood. These accumulations can be a fire hazard. After operation in mud or sand, have the brake linings clean ...

Engine Overheating
If the vehicle has the Duramax® Diesel engine, see the Duramax Diesel Supplement for more information. The vehicle has several indicators to warn of engine overheating. There is a coolant temperatu ...