GM Service Manual Online
For 1990-2009 cars only

Object Number: 1839823  Size: A3

The ignition switch has four different positions.

To shift out of P (Park), the ignition must be in the ON/RUN or ACC/ACCESSORY and the brake pedal must be applied.

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 ignition and steering column. You will only be able to remove the key when the ignition is turned to LOCK/OFF. If you have an automatic transmission, the ignition switch cannot be turned to LOCK/OFF unless the shift lever is in P (Park). If you have a manual transmission, the ignition switch can be turned to LOCK/OFF in any shift lever position.

Caution: If you have a manual transmission removing the key from the ignition switch 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 to ACC/ACCESSORY.

ACC (ACC/ACCESSORY):  This is the position in which you can operate some of the electrical accessories. It unlocks the steering wheel and ignition.

(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. A warning tone will sound when the driver door is opened. the ignition is in LOCK/OFF or ACC/ACCESSORY, and the key is in the ignition.

Shift Lock Release

For vehicles with an automatic transmission, the following procedure allows the ignition to be turned to LOCK/OFF, and for the removal of the ignition key, in case of a dead battery or low voltage battery.

  1. Make sure the shift lever is in P (Park).

  2. Object Number: 1608609  Size: B3
  3. Using a tool, remove the cover to the lock release access hole, located at the bottom of the steering column.

  4. Object Number: 1608605  Size: B3
  5. Place your finger into the access hole and locate the plunger.
  6. Press and hold the plunger toward the driver door while turning the ignition key to LOCK/OFF.
  7. Remove the key.

Have the vehicle serviced at your dealer/retailer as soon as possible.