Abstract: A freezing diagnosing device to be installed in an engine includes an ambient temperature sensor, a liquid temperature sensor, and a freezing determination unit. The ambient temperature sensor detects an ambient temperature. The liquid temperature sensor detects the temperature of a liquid held in the engine. The freezing determination unit determines that a freezing state of a pipe coupled to a pressure sensor in the engine is established when one or both of a first condition and a second condition are satisfied. The first condition is that the ambient temperature detected by the ambient temperature sensor is equal to or less than a first threshold. The second condition is that the temperature of the liquid detected by the liquid temperature sensor is equal to or less than a second threshold.

Abstract: An oil temperature sensor diagnostic device is configured to detect an abnormality in an oil temperature sensor provided in a vehicle, the vehicle including the oil temperature sensor configured to detect an oil temperature of a lubricant of an engine, and an idle-stop controller configured to execute an idle-stop control. The oil temperature sensor diagnostic device includes: a diagnostic value setting module configured to set a diagnostic value that is increased according to an elapsed running time; and an abnormality determination module configured to determine an abnormality of the oil temperature sensor in a case in which a rise in the oil temperature computed on a basis of an output of the oil temperature sensor is small compared to an amount of increase in the diagnostic value.

Abstract: A freezing diagnosing device to be installed in an engine includes an ambient temperature sensor, a liquid temperature sensor, and a freezing determination unit. The ambient temperature sensor detects an ambient temperature. The liquid temperature sensor detects the temperature of a liquid held in the engine. The freezing determination unit determines that a freezing state of a pipe coupled to a pressure sensor in the engine is established when one or both of a first condition and a second condition are satisfied. The first condition is that the ambient temperature detected by the ambient temperature sensor is equal to or less than a first threshold. The second condition is that the temperature of the liquid detected by the liquid temperature sensor is equal to or less than a second threshold.

Abstract: An oil temperature sensor diagnostic device is configured to detect an abnormality in an oil temperature sensor provided in a vehicle, the vehicle including the oil temperature sensor configured to detect an oil temperature of a lubricant of an engine, and an idle-stop controller configured to execute an idle-stop control. The oil temperature sensor diagnostic device includes: a diagnostic value setting module configured to set a diagnostic value that is increased according to an elapsed running time; and an abnormality determination module configured to determine an abnormality of the oil temperature sensor in a case in which a rise in the oil temperature computed on a basis of an output of the oil temperature sensor is small compared to an amount of increase in the diagnostic value.