Patent ID: 6999867

Claim:
An engine control unit for controlling operation of a vehicle engine provided with power supply means for receiving a power from an external power source and supplying a power required for the engine control unit, the engine control unit comprising: unit disconnection detecting means for detecting that the engine control unit is disconnected from the external power source and that the engine control unit is connected to the external power source, means for determining change in voltage from the external power source where the change in voltage is a sudden decrease in voltage or is a voltage in the vicinity of 0V for a period of time, and storage means for staring predetermined information, wherein the engine control unit stores an engine stop flag in the storage means when disconnection of the engine control unit is detected by the unit disconnection detecting means or when there is a sudden decrease in voltage or when there is a voltage in the vicinity of 0V for a period of time detected by the change in voltage determining means, said engine control unit permitting operation of the engine for a predetermined time period in the case where the engine stop flag is stored in the storage means.