GM Service Manual Online
For 1990-2009 cars only

In order to properly evaluate the lock system after installing a replacement part, make the following operational checks:

  1. Insert the key into the cylinder.
  2. While holding the key in the neutral (pull-out) position, actuate the inside locking button to the fully locked position. Move the inside locking button back to the full unlocked position.
  3. There must be no forced movement of the key out of the neutral position during the entire cycle.

  4. Ensure that the key can be removed when the inside locking button is held in both the fully locked and unlocked positions.
  5. Turn the key to the fully locked position. Return the key to the neutral (pull-out) position.
  6. Actuate both the outside and the inside handles in order to ensure that the door will not open.

  7. Turn the key to the fully unlocked position. Return the key to the neutral (pull-out) position.
  8. Actuate both the outside and inside handles in order to ensure that the door will open.