WARNING: This page is about a different car, the 2003 GMC Sonoma, 2003 GMC Jimmy, 2003 Chevrolet S10 Pickup, and 2003 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.
The number below refers to the step number on the diagnostic table.
2. This step tests he functionality of the transfer case shift control system.
Fig 1: Diagnostic System Check (Transfer Case Will Not Complete a Mode or Range Shift)