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

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

Become very familiar with the SCMs 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 a SCM only if the diagnostic procedures specifically direct you to do so. Every input to the SCM and every output from the SCM is short to ground/short to battery protected. Therefore, a SCM 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 SCM are very reliable and not the likely cause of a system malfunction. A SCM replacement before a complete diagnosis will usually result in a recurrence of the original complaint malfunction.

The SCM has the ability to store DTCs as current or history codes. When the SCM stores a DTC, the SCM may send a massage on the serial data line to the Instrument Panel Cluster (IPC) to display a warning message indicating a DTC is current. For most DTCs, the SCM will NOT display a warning message. Current DTCs can be stored in two classifications: latched, and unlatched. Latched current codes are those indicating a malfunction is present, but will still remain current even after the malfunction no longer exists. These current codes will continue to display as current until the ignition is cycled OFF then ON. Unlatched codes will clear as soon as the malfunction is no longer present and does not require the ignition to be cycled. History DTCs are those indicating that the SCM previously detected a malfunction which later disappeared. The reason could be either that the malfunction is intermittent, only happening occasionally, or that the system for which the DTC is set is not currently being operated. History DTCs are intermittent malfunctions and must be diagnosed differently than current DTCs. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.