System and method for detecting short-to-ground fault

A fault detection system for detecting a resistive short-to-ground fault in an injector driver circuit, the fault detection system comprising:

• a state detection module configured to detect whether the injector driver circuit is in an inactive state;
• a pull-up module operatively coupled to the state detection module, the pull-up module comprising a pull-up resistor connected to a low-side output of the fuel injector, wherein the pull-up module is configured to:
• selectively enable a pull-up voltage applied across the pull-up resistor only when the injector driver circuit is in the inactive state;
• and
• determine an intersection voltage at a point between the pull-up resistor and the low-side output;
• and
• an output module operatively coupled to the state detection module and the pull-up module, wherein the output module is configured to compare the intersection voltage with a predetermined reference voltage.

An injector driver circuit for a fuel injection system having a plurality of fuel injectors, the injector driver circuit comprising:

• a power source;
• a selector switch associated with each of the plurality of fuel injectors and located on a low-side output of each of the injectors, each selector switch being configured to selectively connect and disconnect an associated fuel injector to allow power from the power source to pass through the associated fuel injector;
• and
• a fault detection system configured to detect a resistive short-to-ground fault in the injector driver circuit, the fault detection system comprising:
• a state detection module operatively coupled to the selector switch of at least one of the fuel injectors, wherein the state detection module is configured to detect a state of the injector driver circuit;
• a pull-up module operatively coupled to the state detection module, the pull-up module comprising a pull-up resistor connected across the low-side output of at least one of the plurality of fuel injectors, wherein the pull-up module is configured to:
• selectively enable a pull-up voltage applied across the pull-up resistor only when the injector driver circuit is in an inactive state;
• and
• determine an intersection voltage at a point between the pull-up resistor and the low-side output;
• and
• an output module operatively coupled to the state detection module and the pull-up module, wherein the output module is configured to compare the intersection voltage with a predetermined reference voltage.