Fault diagnosis apparatus and method for vehicle control system

摘要

This invention relates to a fault diagnosis apparatus for a vehicle control system. The fault diagnosis apparatus is useful in diagnosing a fault of an electronic component mounted on a vehicle, especially when the fault has led to such a control as deteriorating exhaust gas. It is an object of this invention to minimize an increase in the manufacturing cost upon incorporation of such a fault diagnosis apparatus. According to this invention, the vehicle control system has an automatic transmission operation state detection sensor, an engine operation state detection sensor, an automatic transmission control unit and an engine control unit. For the diagnosis of a fault of at least one of the sensors and control units, the fault diagnosis apparatus comprises a fault determining unit, a code converter, a fault determining unit, a code converter, an ISO converter and a determining and diagnosing tester.