GM Service Manual Online
For 1990-2009 cars only
    • Place the ignition key into the "LOCK" position. If the key can not be rotated to the lock position, lift the adjuster button on the park lock cable and slide the adjuster rearward in vehicle (compressing the spring) and rotate the key into the locked position.
  1. Place the park lock cable adjuster button into the up (unlocked) position.
  2. Grasp the cable at the front of the spring and move it forward in vehicle to remove the slack and release the cable.
  3. Move the cable adjuster rearward in vehicle 1.5 mm (1/16  inches) from the previous position. While holding this postiion, push the adjuster button down flush with the adjuster body.
  4. If the shift lever will move out of the park position with the key in the"LOCK" position or the key lock cylinder will not turn to the "LOCK" position with the shift lever in the "PARK" position the readjust the park lock cable or refer to Steering, Suspension, Wheels and Tires DIagnosis.