To improve decision precision by employing an abnormality judging logic wherein a temperature sensor, which displays a detected temperature in a normal area, is judged abnormal when it does not correctly detect temperature rising, so that an erroneous detection is avoided when the temperature sensor becomes out of order while containing a resistance value corresponding to the temperature in normal area.
An abnormality judging device 11 is applied with an oil temperature Tat, a throttle open-degree Tvo, an engine rotation speed Ne, and a car speed V from an oil temperature sensor 12, a throttle open-degree sensor 13, an engine rotation speed sensor 14, and a car speed sensor 15, respectively. A lapse of time is measured in which a working oil temperature Tat of an automatic transmission is continuously contained in any one of temperature zones which is formed by dividing a temperature zone which is lower than a normal zone in temperature set for oil temperature, and, when a measured lapse of time reaches a specified time, it is judged that an abnormality exists with the oil temperature sensor, to actuate an alarming device 22.
SHINSO YOSHIHIDE
SHIROSAKI TAKENORI
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