Lock Cylinder Tumbler Operation
WARNING: This page is about a different car, the 2005 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
Each of the 4 cut depths on the key has corresponding tumblers sometimes referred to as plates or wafers. The tumbler depth number is stamped on the tumblers for identification. The I/P storage compartment lock cylinder also require a retainer tumbler. The retainer tumbler is not moved by the key, its function is to retain the I/P storage compartment lock cylinder in the lock assembly.