GM Service Manual Online
For 1990-2009 cars only
  1. Hold the coil outer casing with 1 hand.
  2. At the pigtail to coil connection area, press and hold the 2 locking lugs with your other hand.
  3. Rotate the inner portion of the coil clockwise until the coil reaches the stop.
  4. While holding the 2 locking lugs, rotate the inner portion of the coil counterclockwise approximately 2.5 turns. Align the green indexing tab with the window in the coil casing.
  5. Release the 2 locking lugs in order to lock the coil in the centralized position.