首页>
外国专利>
Fault diagnosis of IC engine exhaust gas recirculation system - detecting pressure change when control valve is operated, and checking whether cooling water temp., air intake temp. or engine oil temp. are above reference for correct operation of sensor
Fault diagnosis of IC engine exhaust gas recirculation system - detecting pressure change when control valve is operated, and checking whether cooling water temp., air intake temp. or engine oil temp. are above reference for correct operation of sensor
A feedback valve is periodically operated during operation of the engine so that a pressure sensor forming part of the control system can determine whether a resulting pressure change within the air inlet system or exhaust gas outlet system lies within a defined range. A fault is diagnosed depending on the outcome of this test. A switch-on step is used to decide whether the pressure sensor can operate normally taking account at least of the cooling water temp., inlet air temp. or engine oil temp. compared to a lower operating threshold when the engine is started. The fault diagnosis is declared invalid if the temp. is too low. ADVANTAGE - Eliminates faulty diagnosis, e.g. in freezing conditions.
展开▼
