Patent ID: 8412440
Filing Date: 2013-04-02
Classification: F02D

Abstract:
1. A pressure sensor failure diagnosis method in a common rail type fuel injection control apparatus, wherein a pressure control valve is provided on a fuel return path from a common rail, and a rail pressure detected by a pressure sensor can be controlled to match a target rail pressure that is calculated based on operational information of an engine, through drive control of the pressure control valve, wherein the pressure control valve is driven by energization at a current value that is obtained by correcting, using a predetermined correction coefficient, a current value that is determined in accordance with the target rail pressure, based on predetermined drive characteristics of the pressure control valve that are stored in advance, and wherein the predetermined correction coefficient is calculated for the target rail pressure, using a predetermined arithmetic expression, based on the current value determined in accordance with the predetermined drive characteristics of the pressure control valve and a current value by which the pressure control valve is energized to cause a rail pressure detected by the pressure sensor to match the target rail pressure or to fall within a predetermined acceptable range, while the correction coefficient is stored and updated through learning processing every time the correction coefficient is calculated, along with the rail pressure at the time of the calculation, the pressure sensor failure diagnosis method being characterized by diagnosing that the pressure sensor has a failure when a learning value of the correction coefficient in the learning processing deviates from a predetermined range.