Key and Lock Cylinder Coding (Seat Back Lock)

The seat back lock cylinder only uses 4 of the 8 cut positions, 5 through 8 (when counting from the key head). The tumbler orientation alternates in adjacent location from side to side.

1. Hold the cylinder assembly (1) so the side with the tumbler spring pocket located closest to the head of the cylinder is facing up.
   Fig 1: Seat Back Lock Cylinder

   Courtesy of GENERAL MOTORS COMPANY
   NOTE: Tumblers identified as 1L to 4L must be inserted in the cylinder side where the first spring pocket is nearest to the back of the key head, tumblers identified as 1R to 4R must be inserted in the opposite side.
   NOTE: The door cylinder tumblers (3) are not self-retaining and must be held in place if the key is not fully inserted into the lock cylinder or until the cylinder (1) is assembled into the seat back latch.
2. Insert tumbler spring (2) in to each of the two spring pockets of the cylinder assembly.
3. The first tumbler (3) to be loaded will be the fifth key cut position, which is the fifth number in the key code. Determine the cut depth at this position and install the corresponding tumbler (3) in to the tumbler slot over the spring nearest the front of the lock cylinder assembly. Install the remaining tumblers following the key code and same process, Pressing the tumblers in place until they are secure.
4. Rotate cylinder assembly. Insert tumbler spring into each of the spring pockets of the cylinder assembly.
5. The first tumbler (3) to be loaded will be the sixth key cut position, the sixth number in the key code. Install the first tumbler in the slot over the spring. Install the remaining tumblers following the key code and same process; pressing the tumblers in place until they are secure.
6. Inspect for correct loading of the tumblers by inserting the key in to the cylinder. All tumblers should drop flush with the lock cylinder body diameter.
7. Verify the key position for inserting the lock into the handle.