System Diagnosis

Perform the System Check Diagnostic System Check and refer to the Symptom Table. Testing and Inspection Refer to Computer System Diagnosis for the appropriate diagnostic procedures. Computers and Control Systems

Important
^ Do NOT replace the Body Function Controller (BFC) unless a Diagnostic Trouble Code (DTC) remains Current after all DTC tables have been executed. NEVER replace the BFC based on History codes.
^ The BFC is connected to the Class 2 serial data link and is capable of setting Diagnostic Trouble Codes. The history DTC codes (a history DTC code is a fault that disappears in the next ignition cycle) can be especially useful in diagnosing an intermittent problem.

For a complete list of Diagnostic Trouble Codes refer to Body Control Module. Body Control Module