Method for diagnosing variable valve timing system
AssigneeHyundai Motor Company
InventorYong Sik Kim
Life of this patent
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Abstract
A method for diagnosing a variable valve timing system configured for enhancing precision of diagnosis regarding a variable valve timing system by precisely diagnosing whether an oil pressure detecting device of the variable valve timing system normally operates, may include a normal operation time determining operation of determining a normal operation time of an oil pressure detecting device to determine whether the oil pressure detecting device is normal after an engine starts, and a diagnosing operation of diagnosing whether the oil pressure detecting device is normal according to whether the oil pressure detecting device of the VVT system is turned off within the normal operation time or whether oil pressure reaches reference pressure.
Claims3
A method for diagnosing a variable valve timing (VVT) system, the method comprising:
- a normal operation time determining operation of determining a normal operation time of an oil pressure detecting device to determine whether the oil pressure detecting device is normal after an engine starts;
- and
- a diagnosing operation of diagnosing whether the oil pressure detecting device is normal according to whether oil pressure reaches a reference pressure within the normal operation time,
- wherein, in the diagnosing operation,
- in a response that a time which has lapsed after the engine started exceeds the normal operation time, a forcible operation command signal is provided to the VVT system, and
- in a response that the VVT system normally operates according to the forcible operation command signal, the oil pressure detecting device is diagnosed to have a fault,
- wherein the normal operation time is determined according to a temperature of a coolant of the engine, a soak time, and a temperature of oil.
Dependencies are inferred from the claim text.