Throttle valve abnormality determination device
A throttle valve abnormality determination device includes a permission/rejection determination unit configured to determine whether or not to permit a sticking determination of a throttle valve. The determination unit is configured to prohibit the sticking determination if a first temperature, which is a temperature in a passage through which intake air flows, is less than or equal to a freezing temperature at which the throttle valve may be frozen when an engine is started and, after prohibiting the sticking determination, permit the sticking determination if an integrated value of a heat amount conversion value based on a second temperature, which is a temperature in the passage, and an intake air amount exceeds a threshold value when the second temperature is greater than or equal to a de-freezing temperature at which a frozen portion of the throttle valve is de-frozen.
1. A throttle valve abnormality determination device comprising:
a first temperature acquisition unit configured to acquire a first temperature that is a temperature in a passage through which intake air flows;
a second temperature acquisition unit configured to acquire a second temperature that is a temperature in the passage;
an air amount acquisition unit configured to acquire an intake air amount that is a mass flow rate of the intake air; and
a permission/rejection determination unit configured to determine whether or not to permit a sticking determination of a throttle valve based on the first temperature, the second temperature, and the intake air amount, wherein
the permission/rejection determination unit is configured to:
prohibit the sticking determination if the first temperature is less than or equal to a freezing temperature at which the throttle valve may be frozen when an engine is started; and
after prohibiting the sticking determination, permit the sticking determination if an integrated value of a heat amount conversion value based on the second temperature and the intake air amount exceeds a threshold value when the second temperature is greater than or equal to a de-freezing temperature at which a frozen portion of the throttle valve is de-frozen.
2. The throttle valve abnormality determination device according to claim 1 , wherein the permission/rejection determination unit is configured to hold a heat amount conversion map that sets the heat amount conversion value corresponding to the second temperature and the intake air amount and calculate the heat amount conversion value by selecting a value corresponding to the second temperature and the intake air amount from the heat amount conversion map.
3. The throttle valve abnormality determination device according to claim 1 , wherein
the engine includes a forced induction device that turbocharges the intake air and a cooler that cools the intake air turbocharged by the forced induction device, wherein the forced induction device and the cooler are located at an upstream side of the throttle valve, and
the second temperature acquisition unit is configured to acquire a temperature of a location between the cooler and the throttle valve as the second temperature.
4. The throttle valve abnormality determination device according to claim 3 , wherein the first temperature acquisition unit is configured to acquire, as the first temperature, a temperature of an upstream side of a compressor that forms the forced induction device.
5. The throttle valve abnormality determination device according to claim 1 , wherein the air amount acquisition unit is configured to acquire a detection value of an intake air amount sensor as the intake air amount.