GM Service Manual Online
For 1990-2009 cars only

Object Number: 1839835  Size: A3

With the key in the ignition switch, you can turn to four different positions.

LOCK (A): This position locks the ignition. It also locks the transmission on automatic transmission vehicles. It will locks the steering wheel on manual transmission vehicles when the key is removed. It is a theft-deterrent feature. You will only be able to remove your key when the ignition is turned to LOCK.

If you have an automatic transmission, the ignition switch cannot be turned to LOCK unless the shift lever is in PARK (P).

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 it is, turn the steering wheel left and right while you turn the key hard. If none of this works, then your vehicle needs service.

ACC (ACCESSORY) (B): This is the position in which you can operate your electrical accessories or items plugged into the accessory power outlets. On automatic transmission vehicles, this position unlocks the ignition. On manual transmission vehicles, it unlocks the ignition and steering wheel . Use this position if your vehicle must be pushed or towed.

ON (C):  This is the position that the switch returns to after you start your engine and release the switch. The switch stays in ON when the engine is running. But even when the engine is not running, you can use ON to operate the electrical accessories and to display some instrument panel cluster warning and indicator lights. The transmission is also unlocked in this position on automatic transmission vehicles. The battery could be drained if you leave the key in the ACC or ON 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.

START (D): This is the position that starts the engine. When the engine starts, release the key. The ignition switch returns to ON for driving.

When the engine is not running, ACC and ON allows you to operate the electrical accessories, such as the radio or items plugged into the accessory power outlets.

A warning tone will sound if you open the driver's door when the ignition is in ACC or LOCK and the key is in the ignition.

Key In the Ignition

Never leave your vehicle with the keys inside, as it is an easy target for joy riders or thieves. If you leave the key in the ignition and park your vehicle, a chime will sound, when you open the driver's door. Always remember to remove your key from the ignition and take it with you. This will lock your ignition and transmission. Also, always remember to lock the doors.

The battery could be drained if you leave the key in the ignition while your vehicle is parked . You may not be able to start your vehicle after it has been parked for an extended period of time.