Diagnostic Aids
WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Check all connections between the IPC and the rear wheel steering control module for loose or damaged terminals or damaged wiring. Use of the Diagnostic System Check will help ensure that there are not other conditions or DTC's that will cause a loss of communication between modules.