Denso Corporation

Takayoshi Nakamura

Haruyuki Urushihata

Hiroshi Katsurahara

Akikazu Uchida

Jun Tarui

Toshiki Annoura

A variable valve timing control apparatus includes an abnormality determining portion and a valve controller. The abnormality determining portion determines whether there is an abnormality in a system of a VCT phase control in which an oil pressure control valve is controlled in a manner that an actual VCT phase coincides with a target phase. The valve controller controls the oil pressure control valve to drive a lock pin in a locking direction so as to lock the VCT phase when the abnormality determining portion determines that there is an abnormality in the system of the VCT phase control.

Variable valve timing control apparatus

A capacitance sensing section senses a capacitance between first and second electrodes. A temperature sensing section senses fuel temperature. A microcomputer functions as a concentration sensing section and senses a concentration of ethanol contained in fuel based on the capacitance sensed by the capacitance sensing section and the temperature sensed by the temperature sensing section. The microcomputer functions as an abnormality detecting section and performs abnormality determination to determine that an abnormality has occurred in the capacitance sensing section when the capacitance sensed by the capacitance sensing section does not change and the temperature sensed by the temperature sensing section changes. Since a dielectric constant has such a temperature characteristic that the dielectric constant changes with the temperature, the abnormality detecting section can detect occurrence of the abnormality in the capacitance sensing section.

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Kariya, Japan

Takayoshi Nakamura