An electronic control device on a vehicle having a shift transmission operable by a driver includes: a battery; a motor generator; and a three-phase inverter executing an electricity conversion between the battery and the motor generator bi-directionally; a detector detecting a shift down operation; an obtaining device obtaining a negative torque corresponding to the shift down operation; a determination device determining whether the battery is chargeable; and a controller controlling the three-phase inverter to generate the negative torque at the motor generator. When the detector detects the shift down operation, and the determination device determines that the battery is not chargeable, the controller outputs a switching signal to all of three upper arms or all of three lower arms to turn on simultaneously, and outputs a shutdown signal to all of three upper arms or all of three lower arms with executing a PWM control of the shutdown signal.