Load Drive Device and Method of Controlling Fuel Injection Device

Provided is a load drive device for controlling a fuel injection device for a vehicle engine and capable of checking an operation of the fuel injection device with high reliability without actually injecting fuel before starting the engine. The load drive device includes: 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, in which a first monitor line and the second monitor line are connected to the arithmetic device, the first monitor line monitoring the drive instruction from the pre-driver circuit to the first switching element before starting an engine, and the second monitor line monitoring the drive instruction from the pre-driver circuit to the second switching element, and the pre-driver circuit has a first control mode in which the first switching element is turned off and the drive instruction is transmitted to the second switching element, and a second control mode in which the second switching element is turned off and the drive instruction is transmitted to the first switching element.