Test Description

WARNING: This page is about a different car, the 2003 Pontiac Aztek and 2003 Buick Rendezvous. 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.

6. The module which was not communicating on the class 2 serial data circuit may have set Loss of Communication DTCs for those modules that it was monitoring.

Fig 1: DTC U1001-U1254 Diagnostic Procedure (Steps 1-5)
Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC U1001-U1254 Diagnostic Procedure (Steps 6-8)
Courtesy of GENERAL MOTORS CORP.