Title:
EGR FAULT DIAGNOSTIC SYSTEM
Document Type and Number:
Japanese Patent JP2000213423
Kind Code:
A
Abstract:
To provide a method for determining a fault state in an exhaust gas recirculation(EGR) system.
An EGR valve is opened (64), and temperature of an EGR cooler is detected while the EGR valve is open, thereby generating a temperature signal (66). A symmetry signal is generated from the temperature signal, and a frequency component of the symmetry signal is separated by carrying out frequency analysis to the symmetry signal. A magnitude of the main frequency component is evaluated and when the magnitude is out of a diagnostic threshold value, a fault state in an EGR system is indicated.
Inventors:
WANG YUE YUN (US)
MAJORS STEVEN W (US)
MAJORS STEVEN W (US)
Application Number:
JP2000013343A
Publication Date:
August 02, 2000
Filing Date:
January 21, 2000
Export Citation:
Assignee:
CUMMINS ENGINE CO INC
International Classes:
F02D41/02; F02D41/22; F02D45/00; F02M25/07; (IPC1-7): F02M25/07; F02D45/00; F02D41/02; F02M25/07
Attorney, Agent or Firm:
Kazuo Shamoto (4 outside)
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