Control system for diagnosing a malfunctioning of a pressure sensor included in an aftertreatment system of an internal combustion engine

Abstract

The embodiment of the invention provides a control system for diagnosing a malfunctioning of a pressure sensor in an aftertreatment system of an internal combustion engine. The aftertreatment system includes an exhaust gas line, a particulate filter located in the exhaust gas line, a differential pressure sensor sensing a differential pressure of the exhaust gas upstream and downstream of the particulate filter and an exhaust back pressure valve located in the exhaust gas line downstream of the particulate filter. An electronic control unit included in the system is configured to identify when the internal combustion engine is running under a fuel cut-off state and measure a first value of a differential pressure across the particulate filter during the identified fuel cut-off state. The electronic control unit operates the exhaust back pressure valve, after the determination of the first value, toward a predetermined closed position thereof and measures a second value of a differential pressure across the particulate filter while the exhaust back pressure valve is in the predetermined closed position. The electronic control unit calculates a difference between the second value and the first value and identifies a malfunctioning of the differential pressure sensor, if the calculated difference is higher than a predetermined threshold value thereof.

Description

technical field [0001] The invention relates to a control system for diagnosing a malfunction of a pressure sensor included in an aftertreatment system of an internal combustion engine, such as a diesel engine of a motor vehicle. Background technique [0002] It is known that internal combustion engines of motor vehicles are equipped with aftertreatment systems designed to modify the composition of the exhaust gas in order to reduce pollutant emissions. [0003] Some aftertreatment systems may include a particulate filter, such as a diesel particulate filter (DPF), which is designed to capture diesel particulate matter or soot contained in the exhaust. [0004] Over the life of the DPF, the efficiency of this component may be monitored using a differential pressure sensor adapted to sense the differential pressure of the exhaust gases upstream of the DPF and downstream of the DPF. In particular, when the measured differential pressure is below its critical value, the DPF ca...

AI Technical Summary

Problems solved by technology

[0006] It can be observed that if a disconnection of the pipe connecting the differential pressure sensor to the second sensing point occurs, the measured differential pressure is always higher than the critical value, and thus even if the DPF cannot effectively capture the soot substance, also does not identify a DPF fault

[0007] In most internal combustion engines, the disconnection of the tube is a rare event, usually through tampering or faulty repairs, but when the aftertreatment system architecture of the ICE is equipped with an exhaust back pressure valve with exhaust brake function , there is an increased possibility of disconnection (particularly the pipe connecting the differential pressure sensor to a second sensing point located downstream of the DPF), also during ICE active conditions

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