NOX SENSOR INSPECTION PROGRAM, NOX SENSOR INSPECTION DEVICE, INTERNAL COMBUSTION ENGINE AND NOX SENSOR INSPECTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a NOx sensor inspection program, a NOx sensor inspection device, an internal combustion engine and a NOx sensor inspection method which prevent unexpected failure of a NOx sensor associated with time degradation of a heater to heat a sensor element.SOLUTION: An inspection program 70 causes a vehicle exterior electronic calculator 81 to execute: a temperature determination procedure to determine whether or not a temperature T1 of a NOx sensor 10 becomes almost equal to an environmental temperature T2; a resistance value acquisition procedure to acquire a resistance value R1 of a heater 15 when the same is energized after the temperature determination procedure; a correction procedure to calculate a corrected resistance value R2 by correcting the acquired resistance value R1 with the environmental temperature T2; and an estimation procedure to estimate replacement time of the NOx sensor 10 associated with degradation of the heater 15 by comparing the corrected resistance value R2 with a replacement determination value Ra.SELECTED DRAWING: Figure 3