ELECTRONIC CONTROL DEVICE

摘要

PROBLEM TO BE SOLVED: To diagnose a failure of a switching element provided in a pilot voltage setting circuit for changing a pilot signal in a stepwise manner.

SOLUTION: An electronic control device includes: a pilot voltage setting circuit connected between a pilot signal line and ground in the electronic control device, and including a serial circuit of a pull-down resistor and a switching element; a processor for controlling the switching element to change a voltage of a pilot signal in a stepwise manner; a diagnosis voltage supply circuit for supplying a failure diagnosis voltage to the pilot signal line; and a failure diagnosis circuit connected to the pull-down resistor and the switching element, for outputting a signal of a failure diagnosis result of the switching element. The processor determines the presence or absence of a failure of the switching element on the basis of an output signal of the failure diagnosis circuit, obtained when allowing the switching element to be turned on and off while controlling the diagnosis voltage supply circuit to supply the failure diagnosis voltage to the pilot signal line.

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