Engine Control Module: Service and Repair

CONTROL UNIT REPLACEMENT

Disconnecting the car's battery will cancel the fault memories of control units. Consequently prior to disconnection of the car's battery, fault memories should be interrogated and faults printed out.

Investigate stored faults.

Ignition must always be switched "Off" before disconnecting or connecting control unit plugs.

Removal and installation of components, relays, fuses, etc. could cause the storage of faults in fault memories of control units capable of self-diagnosis. Consequently fault memories must always be interrogated after working on the electrical system. Stored faults must be investigated and cancelled.