US 2008/0306648 A1 · Abnormality diagnosis system and control system for internal combustion engine

Abstract

An ECU (60) for an engine (10, 70) monitors a change of an actual fuel pressure (NPC), when a target fuel pressure (PFIN) is changed stepwise. In one abnormality, the time required for the actual fuel pressure to reach the target fuel pressure is equal to that when an actuator (34) operates normally. However, the maximum value of a differential value (dNPC/dt) with respect to time of the actual fuel pressure is different from that when the actuator operates normally. For this reason, a normal range is set in advance for the maximum value of the differential value with respect to time of the actual fuel pressure and when the maximum value of the differential value with respect to time of the actual fuel pressure is out of the normal range, it is determined that the actuator operates abnormally.

Claims19

Dependent claims

An abnormality diagnosis system for an internal combustion engine having an actuator operable to control a controlled variable of an object to be controlled when fuel is converted to rotational energy, the abnormality diagnosis system comprising:

monitoring means for monitoring a change of an operating quantity or the controlled variable of the actuator in a process changing to a target value of the operating quantity or the controlled variable under condition in which the target value is changed;
and
determination means for determining presence or absence of an abnormality in a response characteristic of the actuator based on the monitored change.

Dependencies are inferred from the claim text.

Abnormality diagnosis system and control system for internal combustion engine

Life of this patent

Abnormality diagnosis system and control system for internal combustion engine

Life of this patent

Abstract

Claims19