Diagnosis system for variable valve controller
AssigneeDenso Corporation
InventorsOsamu Fukasawa, Hideki Obayashi
Life of this patent
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Abstract
A control mode of an intake valve lift controller is changed between a low-speed mode and a high-speed mode. Based on the control mode, an ignition timing is adjusted. When a knocking is detected by a knock sensor after the control mode is changed from the low-speed mode to the high-speed mode, it is determined that the intake valve lift controller has a malfunction in which the intake valve lift controller is stuck in the low-speed mode. When a combustion stability is lowered to a predetermined level after the control mode is changed from the high-speed mode to the low-speed mode, it is determined that the intake valve lift controller has a malfunction in which the intake valve lift controller is stuck in the high-speed mode.
Claims4
A diagnosis system for a variable valve controller, the variable valve controller changing a valve profile of an intake valve and/or an exhaust valve from a control mode to another control mode based on a condition of an internal combustion engine, an ignition timing varied according to a change of the control mode, comprising:
- a knock detecting means for detecting a knocking of the internal combustion engine;
- and
- a malfunction diagnosis means for diagnosing whether a malfunction of the variable valve controller exists based on a detecting result by the knock detecting means when the control mode of the variable valve controller is changed.
Dependencies are inferred from the claim text.