Starter-relay control circuit with self fault diagnosis function

摘要

In a starter-relay control circuit, a high-side switching element is connected between a first output line connected to a high-side terminal and an ignition power line connected to the ignition switch. A low-side switching element is connected between a second output line connected to a low-side terminal and a ground line connected to a negative terminal of the battery. A pull-up element is connected between the ignition power line and the first output line. A pull-down element is connected between the ground line and the second output line. A failure detecting unit is connected to the first and second output lines and configured to determine whether a failure wherein the high-side terminal is short-circuited to the positive terminal of the battery occurs based on a voltage of the second output line when the ignition switch is in an off position.