Electronic Control Device and Method for Controlling Electronic Control Device

A highly reliable electronic control device capable of preventing a reverse current at the time of GND disconnection in advance without requiring an additional circuit for reverse current detection is provided as an electronic control device in which a plurality of inductive loads are connected in parallel. There are provided a first high-side switch element that allows conduction between a battery power supply and a first external load; a first low-side switch element that allows conduction between a ground and the first external load; a second high-side switch element that allows conduction between the battery power supply and a second external load; and a second low-side switch element that is connected to the common ground with the first low-side switch element, and allows conduction between the ground and the second external load, synchronous rectification control for ON/OFF-controlling the first high-side switch element and the first low-side switch element is performed during a period in which a target current to the first external load is greater than a predetermined threshold value, and reflux control for ON/OFF-controlling the first high-side switch element while the first low-side switch element is turned off is performed during a period in which the target current to the first external load is equal to or less than the predetermined threshold value.