GM Service Manual Online
For 1990-2009 cars only

Object Number: 1202403  Size: A2

The ignition switch has four different positions.

Caution: On manual transmission vehicles, turning the key to LOCK/OFF will lock the steering column and result in a loss of ability to steer the vehicle. This could cause a collision. If you need to turn the engine off while the vehicle is moving, turn the key only to ACC/ACCESSORY. Do not push the key in while the vehicle is moving.

Notice: Using a tool to force the key to turn in the ignition could cause damage to the switch or break the key. Use the correct key, make sure it is all the way in, and turn it only with your hand. If the key cannot be turned by hand, see your dealer/retailer.

LOCK/OFF: This position locks the steering wheel, ignition, shift lever and transmission. This is the only position in which you can insert or remove the key. The steering can bind with the wheels turned off center. If this happens, move the steering wheel from right to left while turning the key to ACC/ACCESSORY. If this doesn't work, then the vehicle needs service.

ACC/ACCESSORY: This position operates some of the electrical accessories, such as the radio, but not the climate control system.

ON/RUN:  This position can be used to operate the electrical accessories, and to display some instrument panel cluster warning and indicator lights. The switch stays in this position when the engine is running. If you leave the key in the ACC/ACCESSORY or ON/RUN position with the engine off, the battery could be drained. You may not be able to start the vehicle if the battery is allowed to drain for an extended period of time.

START: This is the position that starts the engine. When the engine starts, release the key. The ignition switch returns to ON/RUN for driving. Do not turn the key to START if the engine is running.