EHC line leakage diagnosis method and vehicle exhaust system thereof
AssigneesHyundai Motor Company, Kia Corporation
InventorBon-Chang Koo
Life of this patent
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Abstract
An EHC line leakage diagnosis method can operate a heater of an oxygen detector when satisfying one or more conditions of an engine off time, a coolant temperature, and an outside air temperature by a diagnosis controller upon the key-on of the non-operation of an engine, and then, determine the normality or abnormality of a temperature drop using a change in a temperature value of a signal value and the temperature value detected by the oxygen detector after an air pump is driven, and then confirm the leakage of an exhaust line and a line on the rear end portion of an EHC valve of an air line using the number of times of the occurrence of the abnormality of the temperature drop, and can perform the failure diagnosis without generating the exhaust gas by not operating an engine.
Claims20
An electric heated catalyst (EHC) line leakage diagnosis method, the method comprising:
- driving, by a diagnosis controller, a heater of an EHC system after entry conditions according to an engine state upon key-on of a vehicle are confirmed;
- determining, by the diagnosis controller, a change in temperature using a signal value and a temperature value of an oxygen detector in an exhaust line after an air pump is driven, and confirming, by the diagnosis controller, an occurrence of a temperature drop according to a time lapse;
- and
- confirming, by the diagnosis controller, a line leakage on a rear end portion of a valve using a number of counts of the occurrence of the temperature drop.
A vehicle exhaust system comprising:
- an exhaust line through which an exhaust gas flows;
- an electric heated catalyst (EHC) system including an oxygen detector provided on the exhaust line, an air pump configured to transmit air to an air line connected to the exhaust line, a switching valve configured to open a passage of the air line, a pressure detector configured to detect a pressure on a valve front end portion of the switching valve, and an electric heated catalyst (EHC) purifying the exhaust gas;
- and
- a diagnosis controller configured to confirm satisfaction of temperature conditions of an engine coolant temperature and an outside air temperature under entry conditions according to a key-on and then, confirm occurrence of a temperature drop according to a time lapse depending upon a change in a temperature value of the oxygen detector detected after airflow of the exhaust line by driving the air pump when a heater of the EHC system is driven, and to confirm a line leakage on a rear end portion of the switching valve using a number of counts of the occurrence of the temperature drop.
Dependencies are inferred from the claim text.