Patent ID: 11898477
Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  Y | IPC F

Claim 6:
7. A control method for an internal combustion engine, wherein
an exhaust purification device is disposed in an exhaust passage of the internal combustion engine,
the internal combustion engine is configured to execute a fuel cutoff operation in which an engine output shaft is rotated with fuel supply stopped,
the control method comprises:
calculating a first change amount that is a change amount per unit time of an upstream-side temperature, the upstream-side temperature being a temperature of exhaust gas on an upstream side of the exhaust purification device;
calculating a second change amount that is a change amount per unit time of a downstream-side temperature, the downstream-side temperature being a temperature of exhaust gas on a downstream side of the exhaust purification device;
determining that a deviation between the first change amount during the fuel cutoff operation and the second change amount during the fuel cutoff operation is less than or equal to a threshold; and
determining that the exhaust purification device is in a detached state when it is determined that the deviation is less than or equal to the threshold.