Regal V6-3.8L SC VIN 1 (1998)
Body Control Module: Initial Inspection and Diagnostic Overview
Body Control Module (BCM)
The Body Control Module (BCM) uses information from other vehicle systems, such as the Powertrain Control Module (PCM), in order to perform
some of its functions. Before starting BCM diagnosis, read the circuit information and learn how the BCM operates and interacts with other vehicle
system. Understanding how the BCM operates will reduce diagnostic time, avoid misdiagnosis, and prevent unnecessary parts replacement.
Use a Tech 2 scan tool to diagnose the BCM when specified in the diagnostic tables. A Tech 2 scan tool displays Diagnostic Trouble Codes (DTCs), the
status of BCM inputs and outputs, and commands BCM outputs on and off.
Become very familiar with the BCM capabilities and diagnostic features. These self-diagnostic features are referenced in the diagnostic tables and are
very useful in diagnosing non-DTC setting malfunctions as well.
Replace the BCM only when a diagnostic table specifically direct you to do so. BCM inputs and outputs are protected against shorts to battery or ground.
Therefore, do NOT replace the BCM after repairing a short in the wiring. After repairing the wiring, perform the BCM diagnostic system check to verify
the repair. Most malfunctions related to a vehicle system, such as the BCM, are traceable to faulty wiring, connectors and terminals, and occasionally
some other component. The BCM is a very reliable component and it is not likely the cause of the malfunction. Replacing the BCM before a complete
diagnosis will usually result in a recurrence of the original malfunction.
