Diagnostic Aids
WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
When multiple loss of communication DTCs are stored concurrently, cause is likely to be two opens in Class 2 serial data circuit. Use DTC ID number list to determine which modules are not communicating. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION NUMBER table. See WIRING DIAGRAMS to determine location of opens.