GM Service Manual Online
For 1990-2009 cars only

In order to properly evaluate the lock system after replacements parts have been installed, the following operational inspection must be made:

  1. Insert the key into the lock cylinder. While holding the neutral (pull out) position, actuate the inside locking button to the full locked position and back to the fully unlocked position. There must be no forced movement of the key out of the neutral position during the entire cycle. The key must be able to be removed when the inside locking button is held in both the fully locked and unlocked positions.
  2. Turn the key to the fully locked position and return it to the neutral (pull out) position. Actuate both the outside and the inside door handles to ensure the door will not open.
  3. Turn the key to the fully unlocked position and return it to the neutral (pull out) position. Actuate both the outside and the inside door handles to ensure the door will open.