Diagnostic system for variable valve timing control system
AssigneeDenso Corporation
InventorHiroshi KATSURAHARA
Life of this patent
Estimating the term…
Abstract
A fuel diluting quantity is estimated based on an alcohol concentration of the fuel. A response-deterioration determination value is corrected according to the estimated fuel diluting quantity. The response-deterioration determination value can be properly established even though the responsiveness of the variable valve timing controller is varied due to a variation in viscosity of the lubricant. Thereby, even when the responsiveness of the variable valve timing controller is varied (deteriorated) due to an increase in the fuel diluting quantity, it can be avoided that the computer determines that the variable valve timing controller has a defect.
Claims5
A diagnostic system for a variable valve timing control system including a hydraulic variable valve timing controller adjusting a valve timing of an intake valve and/or an exhaust valve with a lubricant of an internal combustion engine and a diagnosis means for diagnosing the variable valve timing controllers, the diagnostic system comprising:
- an alcohol concentration determination means for detecting or estimating an alcohol concentration of a fuel supplied to the internal combustion engine;
- and
- a fuel diluting quantity estimation means for estimating a fuel diluting quantity based on the alcohol concentration, the fuel diluting quantity representing a fuel quantity mixed with the lubricant, wherein
- the diagnosis means includes a correcting means for correcting a determination condition based on the fuel diluting quantity, and the diagnosis means performs a diagnosis of the variable valve timing controller by means of said corrected determination condition.
Dependencies are inferred from the claim text.