Fault diagnostic system for internal combustion engine and fault diagnostic method for internal combustion engine

摘要

A learning unit learns a difference between a detected value ECT and a detected value RCT when it is determined that the detected value ECT and detected value RCT are stable while an engine is at a stop. A diagnostic unit performs a fault diagnosis for the engine based on the difference between the detected value ECT and detected value RCT having been corrected through use of a learned value learned by the learning unit. Accordingly, a fault diagnostic system for an internal combustion engine and a fault diagnostic method for an internal combustion engine can be achieved in which accuracy in fault diagnosis for the internal combustion engine can be improved and an erroneous diagnosis can be restrained.