Title:
ANOMALY DIAGNOSIS DEVICE FOR EXHAUST GAS RECIRCULATION SYSTEM
Document Type and Number:
Japanese Patent JP3846381
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To suppress a wrong determination when an anomaly determination about an exhaust gas recirculation (EGR) system is made with no reference value stored about travel of an EGR valve.
SOLUTION: An electronic control unit (ECU) calculates, stores and updates a reference value about travel of the EGR valve according to an output value of a lift sensor produced when a command signal for fully closing the EGR valve is output. According to the reference value, a relation between the sensor output value and the EGR valve travel is corrected (Step 330, 360). A deviation is computed between target EGR valve travel corresponding to an engine operating state and the corrected EGR valve travel, and according to a result of comparison between the absolute value of the deviation and a criterion value, whether there is an anomaly in the EGR system or not is determined (Step 330 to 370). In the determination, the criterion value is changed in dependence on whether an initial value of reference value is stored (Step 320: YES) or not (Step 320: NO) (Step 330, 360).
Inventors:
Takahiro Uchida
Yoshiyasu Ito
Atsushi Morikawa
Yoshiyasu Ito
Atsushi Morikawa
Application Number:
JP2002243556A
Publication Date:
November 15, 2006
Filing Date:
August 23, 2002
Export Citation:
Assignee:
TOYOTA JIDOSHA KABUSHIKI KAISHA
International Classes:
F02M25/07; F02D45/00; (IPC1-7): F02M25/07; F02D45/00
Domestic Patent References:
| JP4103865A | ||||
| JP20024950A | ||||
| JP2001173492A |
Attorney, Agent or Firm:
Hironobu Onda
Makoto Onda
Makoto Onda