Test Description
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers on the diagnostic table.
A module which loses power during an ignition cycle will cause other module to set lost communication DTCs.
A module which loses power during an ignition cycle will cause other module to set lost communication DTCs.
The malfunction is due to an open in the class 2 serial data circuit or an open in the module.
The module which was not communicating due to an open in the class 2 serial data circuit may have set lost communication DTCs for those modules that it was monitoring.
The modules which can communicate indicate the module which cannot communicate. You must clear the DTCs from these modules to avoid future misdiagnosis.