Side Door Lock Cylinder Coding
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2005 Isuzu Ascender, 2005 GMC Envoy XUV, 2005 GMC Envoy XL, 2005 GMC Envoy, and 2005 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
The side door lock cylinder has five snap-in tumblers. The number 1-5 positions (beginning closest to the cylinder head) is a brass retainer tumbler. The 6-10 positions are standard tumbler positions. Therefore, only the 6-10 positions are required.