Patent attributes
Driver circuits are provided in correspondence to switching elements of an inverter to output gate signals to the switching elements and built in an IC package in an abnormality detection device (ECU). Motor relays are provided in motor current paths between inter-arm connection points and multi-phase motor windings. Pull-up resistors connect a power supply line and the inter-arm connection points. Pull-down resistors connect the inter-arm connection points and the ground. A checking unit acquires a voltage corresponding to a voltage of each inter-arm connection point as a terminal voltage and checks a short-circuit failure or an open-circuit failure of each motor relay or a disconnection failure of each winding based on the terminal voltage. The pull-up resistors and the pull-down resistors are provided within the IC package in which the driver circuits are built.