Operation CHARM: Car repair manuals for everyone.

Module Replacement

Replace the module only when a diagnostic table specifically directs you to do so. Inputs and outputs are protected against shorts to battery or ground. Therefore, do NOT replace the module after repairing a short in the wiring. Most malfunctions related to a vehicle system are traceable to faulty wiring, connectors and terminals, and occasionally to some other component in the system.

Each module is very reliable and it is not likely the cause of the malfunction. Replacing the module before a complete diagnosis will usually result in a recurrence of the original malfunction.