Diagnosis System of 1 Shift-Gear Switch for Diesel Engine Automobile and the Method for the Same

摘要

PURPOSE: A first-stage gear switch diagnosis device of a diesel engine vehicle and a method thereof are provided to diagnose a disconnection state of the first-stage gear switch by comparing signals of the first-stage gear switch and the current speed range detected according to the traveling state of the vehicle. CONSTITUTION: A first-stage gear switch diagnosis device of a diesel engine vehicle comprises an RPM(Revolutions Per Minute) sensor(2) installed to a crankshaft of an engine, to sense RPM of the engine; a vehicle speed sensor(4) installed to a vehicle, to sense the vehicle speed; a clutch pedal switch(6) installed to a clutch pedal, to sense the operating state of the clutch pedal; a first-stage gear switch(8) informing of first-range shifting according to driver's operation; and an electronic control unit(10). The electronic control unit receives signals of the RPM sensor, the vehicle speed sensor, and the clutch pedal switch, and determines whether the vehicle travels at the speed range of a first-range. The electronic control unit decides a connection error of the first-range gear switch if the determined result is contrary to the signal of the first-range gear switch and stores an error code to detect the connection error of the first-stage gear switch in maintenance work.