Diagnostic system for exhaust gas recirculation device

Patent · Tue Dec 27 04:00:00 EST 1988

OSTI ID:6155220

Tsurusaki, S

A diagnostic system of an exhaust gas recirculation device is described having an exhaust gas recirculation control valve which is arranged in an exhaust gas recirculation passage interconnecting an exhaust passage to an intake passage of an internal combustion engine, the diagnostic system comprising: determining whether the engine is operating in a state at which the recirculation of exhaust gas is to be carried out; detecting a temperature in the exhaust gas recirculation passage downstream of the exhaust gas recirculation control valve; having a count value which is variable between a predetermined first value and a predetermined second value, the count value being changed from the first value toward the second value when the engine is operating in a state where the recirculation of exhaust is to be carried out; means for storing a first temperature detected by the detecting means when the count value is equal to the first value; and second determining means for obtaining a difference between the first temperature and second temperature detected by the detecting means when the count value becomes equal to the second value, to thereby determine that a malfunction has occurred in the exhaust gas recirculation device when the difference is lower than a predetermined value.

• Assignee: Toyota Jidosha Kabushiki Kaisha, Aichi
• Patent Number(s): US 4793318
• OSTI ID: 6155220
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330700* -- Advanced Propulsion Systems-- Emission Control
500200 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION CONTROL
CONTROL
CONTROL EQUIPMENT
DESIGN
EQUIPMENT
EXHAUST GASES
EXHAUST RECIRCULATION SYSTEMS
EXHAUST SYSTEMS
FAILURES
FLOW REGULATORS
FLUID FLOW
FLUIDS
GAS FLOW
GASEOUS WASTES
GASES
MEASURING INSTRUMENTS
METERING
METERS
MONITORING
POLLUTION CONTROL
POLLUTION CONTROL EQUIPMENT
TEMPERATURE MEASUREMENT
VALVES
WASTES