Load drive device and method of controlling fuel injection device

A load drive device comprising:

• a first switching element that is connected to a high-side of a load;
• a second switching element that is connected to a low-side of the load;
• a pre-driver circuit that transmits a drive instruction to the first switching element and the second switching element;
• an arithmetic device that transmits a control instruction to the pre-driver circuit;
• and
• a current cut-off circuit that is provided at least one of between the first switching element and a power supply and between the second switching element and a ground, and directly controlled by the arithmetic device,
• wherein the arithmetic device turns off the current cut-off circuit provided at least one of between the first switching element and the power supply and between the second switching element and the ground, before starting the engine.

A load drive device comprising:

• a first switching element that is connected to a high-side of a load;
• a second switching element that is connected to a low-side of the load;
• a pre-driver circuit that transmits a drive instruction to the first switching element and the second switching element;
• and
• an arithmetic device that transmits a control instruction to the pre-driver circuit,
• wherein
• a monitor line for monitoring a difference in a voltage across the load is connected to the arithmetic device, and
• the arithmetic device monitors the differentiated voltage across the load.

A method of controlling a fuel injection device, comprising:

• turning off a high-side driver before starting an engine;
• operating a pre-driver to output a gate signal to a low-side driver;
• monitoring the gate signal output to the low-side by a CPU via a voltage drop circuit;
• turning off the low-side driver;
• operating the pre-driver to output a gate signal to the high-side driver;
• monitoring the gate signal output to the high-side by the CPU via the voltage drop circuit;
• and
• diagnosing a pre-driver reset mechanism of the pre-driver based on a state of each of the gate signals when the pre-driver is reset to the low-side driver and when the pre-driver is reset to the high-side driver.