The Control Module Id

WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Control Module ID Chart (1 Of 2)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Control Module ID Chart (2 Of 2)

Courtesy of GENERAL MOTORS CORP.

When more than one loss of communication DTC is set in a single module or among multiple modules, diagnose the DTCs in the following order:

Current DTCs before history DTCs except as specified in the diagnostic tables.
The DTC which is reported the most times.
From the lowest number DTC to the highest number DTC.