System and method for diagnosing electrical faults

A system, comprising:

• a load device coupled to an output of an electronic control unit (ECU) via a coaxial cable;
• and
• the ECU, comprising:
• a power supply configured to provide power for the load device;
• a power over coaxial cable (PoC) filter coupled to the output;
• a high side switch (HSS) coupled to the power supply and to the PoC filter via an HSS output line;
• a diode disposed in the HSS output line and configured to substantially eliminate current flow from the output towards the HSS, while allowing current to flow from the HSS towards the load device from the HSS;
• a diode resistor (RD) disposed in parallel with the diode an configured to allow a current to flow past the diode towards the HSS while the HSS is in an off mode and a short-to-battery scenario is occurring;
• and
• a pull down resistor (RPD) disposed between the output line of the HSS and a ground prior to the diode, and configured to pull the voltage at the HSS output down to zero volts while the HSS is in the off mode and an open load scenario has occurred.