Patent ID: 10288015

Abstract:
The invention relates to a method for checking a functionality of a differential pressure measuring unit (31) in an exhaust gas recirculation system (1) of a motor vehicle, and a corresponding exhaust gas recirculation system (1). In an air intake duct (5), a sensor flap (11) is provided downstream of an air filter (9) and upstream of an opening (37) of an exhaust gas recirculation duct (25). This sensor flap (11) is set in two different positions and a value of a pressure drop in the exhaust gas stream is measured for each position as said gas stream flows through an exhaust gas recirculation stream valve (29) provided in the exhaust gas recirculation duct (25). If the measured pressure drop does not significantly change despite the movement of the sensor flap (11), it can be assumed that there is a fault in the differential pressure measuring unit (31). In particular, it is possible to detect when a hose (41), which connects a differential pressure sensor of the differential pressure measuring unit (31) to a connector (35) on the exhaust gas recirculation duct (25) downstream of the exhaust gas recirculation stream valve (29) has torn, slipped off or become blocked.