Method for monitoring functioning of differential pressure sensor in exhaust gas after-treatment system of diesel engine, involves closing defective front terminal or rear terminal with change in stationary measured pressure difference

摘要

The method involves changing position of a waste gas valve (26), so that the exhaust gas back pressure in front of the waste gas valve is increased. A front terminal (23) or a rear terminal (25) of a differential pressure sensor (24) is closed with change in a stationary measured pressure difference by expectancy value or with time limited alteration of the measured pressure difference caused by defect of the front terminal or the rear terminal, where sensor is arranged parallel to a particulate filter (22) arranged in an exhaust gas passage (21). The waste gas valve is formed as a silencer. An independent claim is also included for a device for monitoring function of a differential pressure sensor in an exhaust gas after-treatment system of a combustion engine.