A device for diagnosing a particulate filter suitable for: determining a measured pressure time profile, and a theoretical pressure time profile upstream of the filter, implementing, on each profile: low-pass filtering to obtain a first filtered time profile, second low-pass filtering of the first filtered time profile to obtain a second filtered time profile, calculating a difference between the second filtered time profile and the first filtered time profile, obtaining an absolute value of the calculated difference, and calculating an integral of the absolute value, and, from a comparison between the two integrals, a diagnosis of the particulate filter.

An exhaust gas sensor that detects a specific component included in an exhaust gas includes a sensor element including a detector, an element cover that accommodates the sensor element and has a gas ventilation hole, a heater that heats the sensor element, a heater control section, and an installation state diagnosis section that diagnoses a state of an element cover based on a sensor temperature detected by a sensor temperature detection section. The installation state diagnosis section includes a temperature variation amount calculation section that calculates a sensor temperature variation amount, a temperature variation amount integration section that sums the sensor temperature variation amounts, and an abnormality determination section that determines presence or absence of an abnormal installation based on a comparison result between variation amount integration information of the sensor temperature and a diagnosis threshold value.

A control device comprising a first exhaust temperature calculation part calculating a temperature of exhaust flowing into a PM trapping device as a first exhaust temperature, a second exhaust temperature calculation part calculating a temperature of exhaust flowing out from the PM trapping device as a second exhaust temperature, a rate of change over time calculation part calculating a rate of change over time of the first exhaust temperature and a rate of change over time of the second exhaust temperature, and a judgment part judging if the PM trapping device is in a removed state removed from the exhaust passage based on a difference between the rate of change over time of the first exhaust temperature and the rate of change over time of the second exhaust temperature.

An apparatus includes circuitry configured to calculate a temperature of exhaust flowing into an exhaust after-treatment system as a first exhaust temperature, calculate a temperature of exhaust flowing out from the exhaust after-treatment system as a second exhaust temperature, calculate a rate of change over time of the first exhaust temperature and a rate of change over time of the second exhaust temperature, and judge if the exhaust after-treatment system is in a removed state removed from the exhaust passage based on a difference between the rate of change over time of the first exhaust temperature and the rate of change over time of the second exhaust temperature.

An apparatus includes circuitry configured to calculate a temperature of exhaust flowing into an exhaust after-treatment system as a first exhaust temperature, calculate a temperature of exhaust flowing out from the exhaust after-treatment system as a second exhaust temperature, calculate a rate of change over time of the first exhaust temperature and a rate of change over time of the second exhaust temperature, and judge exhaust after-treatment system if the exhaust after-treatment system is in a removed state removed from the exhaust passage based on a difference between the rate of change over time of the first exhaust temperature and the rate of change over time of the second exhaust temperature.

An apparatus includes circuitry configured to: calculate a temperature of exhaust flowing into an exhaust after-treatment system as a first exhaust temperature, calculate a temperature of exhaust flowing out from the exhaust after-treatment system as a second exhaust temperature, calculate a rate of change over time of the first exhaust temperature and a rate of change over time of the second exhaust temperature, and judge if the exhaust after-treatment system is in a removed state removed from the exhaust passage based on a difference between the rate of change over time of the first exhaust temperature and the rate of change over time of the second exhaust temperature.

An apparatus includes circuitry configured to: calculate a temperature of exhaust flowing into an exhaust after-treatment system as a first exhaust temperature, calculate a temperature of exhaust flowing out from the exhaust after-treatment system as a second exhaust temperature, calculate a rate of change over time of the first exhaust temperature and a rate of change over time of the second exhaust temperature, and judge if the exhaust after-treatment system is in a removed state removed from the exhaust passage based on a difference between the rate of change over time of the first exhaust temperature and the rate of change over time of the second exhaust temperature.

A control device includes a first exhaust temperature calculation part calculating a temperature of exhaust flowing into a PM trapping device as a first exhaust temperature, a second exhaust temperature calculation part calculating a temperature of exhaust flowing out from the PM trapping device as a second exhaust temperature, a rate of change over time calculation part calculating a rate of change over time of the first exhaust temperature and a rate of change over time of the second exhaust temperature, and a judgment part judging if the PM trapping device is in a removed state removed from the exhaust passage based on a difference between the rate of change over time of the first exhaust temperature and the rate of change over time of the second exhaust temperature.

An apparatus includes circuitry configured to: calculate a temperature of exhaust flowing into an exhaust after-treatment system as a first exhaust temperature, calculate a temperature of exhaust flowing out from the exhaust after-treatment system as a second exhaust temperature, calculate a rate of change over time of the first exhaust temperature and a rate of change over time of the second exhaust temperature, and judge if the exhaust after-treatment system is in a removed state removed from the exhaust passage based on a difference between the rate of change over time of the first exhaust temperature and the rate of change over time of the second exhaust temperature.

An apparatus includes circuitry configured to: calculate a temperature of exhaust flowing into an exhaust after-treatment system as a first exhaust temperature, calculate a temperature of exhaust flowing out from the exhaust after-treatment system as a second exhaust temperature, calculate a rate of change over time of the first exhaust temperature and a rate of change over time of the second exhaust temperature, and judge if the exhaust after-treatment system is in a removed state removed from the exhaust passage based on a difference between the rate of change over time of the first exhaust temperature and the rate of change over time of the second exhaust temperature.