METHOD AND SYSTEM FOR DIAGNOSING COMMON RAIL DIESEL ENGINE

摘要

Disclosed are a method and a system for diagnosing a common rail diesel engine. The method for diagnosing a common rail diesel engine may include setting a time when a pressure of a common rail becomes a first set pressure to a diagnosis start time and neglecting a state of the common rail until the pressure of the common rail decreases from the first set pressure to a second set pressure which is a diagnosis end pressure, verifying a time when the pressure of the common rail becomes the second set pressure and determining the time as a diagnosis end time when the pressure of the common rail becomes the second set pressure, calculating a diagnosis time as an elapsed time from the diagnosis start time to the diagnose end time, and diagnosing that fuel leaks from the common rail when the diagnosis time is shorter than a diagnosis set time by comparing the diagnosis time with the diagnosis set time.

主权项

1. A method for diagnosing a common rail diesel engine, comprising:
determining whether a diagnosis request signal for requesting a diagnosis of the common rail diesel engine is input while the common rail diesel engine is driven; increasing a pressure of a common rail to a set pressure if the diagnosis request signal is input; stopping the common rail diesel engine and neglecting the common rail diesel engine when the pressure of the common rail increases to the set pressure and until the pressure of the common rail decreases to a first set pressure which is a diagnosis start pressure; setting a time when the pressure of the common rail becomes the first set pressure to a diagnosis start time and neglecting a state of the common rail until the pressure of the common rail decreases from the first set pressure to a second set pressure which is a diagnosis end pressure; verifying a time when the pressure of the common rail becomes the second set pressure and determining the time as a diagnosis end time when the pressure of the common rail becomes the second set pressure; calculating a diagnosis time as an elapsed time from the diagnosis start time to the diagnose end time; and diagnosing that fuel leaks from the common rail when the diagnosis time is shorter than a diagnosis set time by comparing the diagnosis time with the diagnosis set time.