An apparatus for controlling the application of electrical power to a load includes a controller, a controllable high side driver electrically connected to a first electrical terminal of the load, and a controllable low side driver electrically connected to a second electrical terminal of the load. The apparatus also includes a diagnostic circuit configured to sense and identify an open load fault condition, a high-side short circuit to battery fault condition, a low-side short circuit to ground fault condition, a high-side short circuit to ground fault condition, a low-side short circuit to battery fault condition, and a short circuited load fault condition. The diagnostic circuit is also configured to sense and identify a condition wherein none of the open load, high-side short circuit to battery, low-side short circuit to ground, high-side short circuit to ground, low-side short circuit to battery, and short circuited load fault conditions are present.