Self-diagnosis system for auxiliary air control system of internal combustion engine
First Claim
1. A self-diagnosis system for an auxiliary air control system of an internal combustion engine having an auxiliary air control valve, provided in an auxiliary air passage which bypasses a throttle valve of an air intake system of said engine, for controlling the amount of air inducted through said auxiliary air passage, comprising:
- first means for detecting the amount of air inducted through a main air intake passage of said engine;
second means comparing the amount of air detected by said first means while said throttle valve is fully closed with a value calculated according to the opening angle command signal for said auxiliary air control valve, said second means judging that said auxiliary air control system is malfunctioning if said intake air amount detected by said first means is larger than said calculated value.
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Accused Products
Abstract
A self-diagnosis system for an auxiliary air control system of an internal combustion engine having an auxiliary air control valve provided in an auxiliary air passage bypassing a main throttle valve, comprises an air flow meter for detecting the amount of intake air, a control unit diagnosing malfunction of the air flow meter and comparing the amount of air inducted when the main throttle valve is fully closed with a value calculated according to the opening angle of the auxiliary air intake control valve. The control unit deems that the auxiliary air control system has malfunctioned only when the amount of intake air is larger than the calculated valve. In the device according to the invention, the malfunction of auxiliary air control system can be detected within a relatively short time, such as 1 sec, and the malfunction can be detected regardless of the engine speed.
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Citations
20 Claims
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1. A self-diagnosis system for an auxiliary air control system of an internal combustion engine having an auxiliary air control valve, provided in an auxiliary air passage which bypasses a throttle valve of an air intake system of said engine, for controlling the amount of air inducted through said auxiliary air passage, comprising:
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first means for detecting the amount of air inducted through a main air intake passage of said engine; second means comparing the amount of air detected by said first means while said throttle valve is fully closed with a value calculated according to the opening angle command signal for said auxiliary air control valve, said second means judging that said auxiliary air control system is malfunctioning if said intake air amount detected by said first means is larger than said calculated value. - View Dependent Claims (2, 3, 4, 5)
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6. A self-diagnosis system for an auxiliary air control system of an internal combustion engine having an auxiliary air control valve, provided in an auxiliary air passage which bypasses a throttle valve of an air intake system of said engine, for controlling the amount of air inducted through said auxiliary air passage, comprising:
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first means for detecting the amount of air inducted through a main air intake passage of said engine; second means comparing the amount of air detected by said first means while said throttle valve is fully closed with a value calculated according to the opening angle command signal for said auxiliary air control valve, said second means judging that said auxiliary air control system is malfunctioning if said intake air amount detected by said first means is larger than said calculated value; third means for diagnosing malfunction of said first means, said third means outputting a signal indicative of the operational condition of said first means; and said second means starting comparison between said intake air amount and said calculated value when said third means judges that said first means is operating normally. - View Dependent Claims (7, 8, 9, 10)
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11. A method for self-diagnosing malfunction of an auxiliary air control system for an internal combustion engine having an auxiliary air control valve, provided in an auxiliary air passage which bypasses a throttle valve of an air intake system of the engine, for controlling the amount of air inducted through said auxiliary air passage, comprising steps of:
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(a) judging the opening angle of said throttle valve; (b) judging the operational condition of first means for detecting the amount of air inducted through a main air intake passage of said engine; (c) judging the operational condition of a starter switch; (d) judging the rotational speed of said engine; (e) comparing an actual battery voltage with a predetermined voltage value; (f) deriving the amount of air inducted through said auxiliary air passage when said throttle valve is fully closed, said first means is operating normally, said starter switch is OFF, said engine is in operation, and said battery voltage is larger than said predetermined voltage value; (g) comparing a calculated value of auxiliary air passage induction with the amount of air inducted through said main air intake passage of said engine; (h) incrementing a counter when the amount of air inducted through said main air intake passage is larger than said calculated value for auxiliary air passage; (i) comparing said count value with a predetermined count value; and (j) judging that said auxiliary air control system has malfunctioned if said count value accumulated by repeating the sequential process of steps (a) to (i) is larger than said predetermined count value. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification