Half-bridge driver fault diagnostic system and method

An apparatus for controlling the application of electrical power to a load having a first electrical terminal and a second electrical terminal, the apparatus comprising:

• a controller;
• a high side driver electrically connected to a voltage supply and to the first electrical terminal of the load, the high side driver controllable to an on state wherein current flow from the voltage supply to the load is enabled and to an off state wherein current flow from the voltage supply to the load is disabled;
• a low side driver electrically connected to the second electrical terminal of the load and to a ground connection, the low side driver controllable to an on state wherein current flow from the load to the ground connection is enabled and to an off state wherein current flow from the load to the ground connection is disabled;
• a diagnostic circuit configured to sense a fault condition and to generate a signal indicative of the fault condition;
• wherein the diagnostic circuit is configured to sense and identify a first fault condition wherein the first fault condition is an open load fault condition;
• wherein the diagnostic circuit is configured to sense and identify a second fault condition wherein the second fault condition is a high-side short circuit to battery fault condition;
• wherein the diagnostic circuit is configured to sense and identify a third fault condition wherein the third fault condition is a low-side short circuit to ground fault condition;
• wherein the diagnostic circuit is configured to sense and identify a fourth fault condition wherein the fourth fault condition is a high-side short circuit to ground fault condition;
• wherein the diagnostic circuit is configured to sense and identify a fifth fault condition wherein the fifth fault condition is a low-side short circuit to battery fault condition;
• wherein the diagnostic circuit is configured to sense and identify a sixth fault condition wherein the sixth fault condition is a short circuited load fault condition;
• wherein the diagnostic circuit is configured to sense and identify a condition wherein none of the first fault condition, the second fault condition, the third fault condition, the fourth fault condition, the fifth fault condition, and the sixth fault condition are present.