FAULT DETECTION DEVICE OF EXHAUST GAS RECIRCULATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a fault detection device of an exhaust gas recirculation device which can detects faults of an EGR valve while suppressing an influence caused by a relationship between magnitudes of intake pressure and exhaust pressure.

SOLUTION: An ECU 70 performs processing for taking out pulsation from an intake pipe pressure value (step S202). The ECU 70 applies FFT operation processing to an output waveform of an intake pressure sensor 32 which is obtained by sampling processing, and performs extraction processing for extracting a "frequency component corresponding to a cycle of exhaust pulsation". The ECU 70 performs processing for determining whether nor not a magnitude of the pulsation (magnitude of amplification) extracted in the step 202 exceeds a threshold (step S204). When the magnitude of the amplification exceeds the threshold, the ECU 70 performs processing for determining that full-open faults have occurred in the EGR valve (step S206).

COPYRIGHT: (C)2012,JPO&INPIT