Alternator - BOSCH: Operation

Alternator diodes convert AC current to DC current. The SMEC monitors input and output of the charging system, making sure it is working properly. The engine controller will store in memory any failures within the charging system. The SMEC translates failures into fault codes when on-board diagnostics are entered.

The system's self-diagnostic abilities, if used properly, can simplify testing. The engine controller monitors several engine control system circuits. If a problem is sensed with a monitored circuit, a fault code is stored in the SMEC memory. The check engine light illuminates and system enters limp-in mode. In this mode, engine controller tries to compensate for the component failure by substituting information from other sources until repairs can be made.