Diagnosis method for liquefied petroleum injection fuel pump

摘要

A method for diagnosing a Liquefied Petroleum Injection fuel pump includes the steps of: inputting an engine Revolutions Per Minute (RPM) and a fuel pump Pulse Width Modulation (PWM) signal into an Electronic Control Unit (ECU) of an interface box; determining whether the RPM indicates that the engine is idling; if the engine is not idling, setting a diagnosis time of the PWM signal to a duration longer than the time the engine takes to deactivate after turning off an LPG switch; determining the operation state of the fuel pump by analyzing the PWM signal; and illuminating a warning lamp if the fuel pump is detected to be operating abnormally or a signal line connecting the fuel pump and the interface box is detected to be disconnected.