2008 GMC Acadia Owner's Manual - Page 108

Ignition Positions With the key in the ignition, you can turn it to four different positions. B (ACC/ACCESSORY): This position allows you to use things like the radio and the windshield wipers while the engine is off. This position will also allow you to turn off the engine. C (ON/RUN): This is the position that the switch returns to after you start your engine and release the key. The switch stays in ON/RUN when the engine is running. But even when the engine is not running, you can use ON/RUN to operate your electrical power accessories, and to display some instrument panel warning lights. The battery could be drained if you leave the key in the ACC/ACCESSORY or ON/RUN position with the engine off. You may not be able to start your vehicle if the battery is allowed to drain for an extended period of time. D (START): This position starts the engine. When the engine starts, release the key. The ignition switch will return to ON/RUN for normal driving. In order to shift out of PARK (P), ignition must be in ON/RUN or ACC/ACCESSORY and the regular brake pedal must be applied. Notice: Using a tool to force the key from the ignition switch could cause damage or break the key. Use the correct key and turn the key only with your hand. Make sure the key is all the way in. If none of this works, then your vehicle needs service. A (LOCK/OFF): This is the only position in which you can remove the key. This position locks the ignition and transmission. If the steering wheel is locked, move it from right to left and turn the key to ACC/ACCESSORY. If none of this works, then your vehicle needs service. 2-26