Body Control Module (SBM)

The Body Control Module (SBM) uses information from other systems in order to execute some functions. Therefore, before further diagnosis, review the general information on how the SBM computer system operates and how each system interacts with the SBM. This will save diagnostic time, future misdiagnosis, and unnecessary parts replacement.

Use a scan tool in order to diagnose the SBM when referred to in diagnostic procedures. In addition to displaying DTCs, the SBM displays the input status and the data values used. The SBM also cycles many of the systems ON and OFF. Any of these features can be selected using the scan tool.

Become very familiar with the SBM capabilities and diagnostic features. These self-diagnostic features are referenced in the DTC tables and are very useful in diagnosing non-DTC setting malfunctions as well.

Replace the SBM only if the diagnostic procedures specifically direct you to do so. Every input to the SBM and every output from the SBM is short to ground/short to battery protected. Therefore, the SBM does not automatically need to be replaced when a short is found in the wiring. Repair the wiring first. Then check the system for further problems. Most system malfunctions are traceable to faulty wiring and connectors, and occasionally components. The SBM is very reliable and not the likely cause of a system malfunction. SBM replacement before a complete diagnosis will usually result in a recurrence of the original complaint malfunction.