Strategy for EOBD Compliant Plausibility Check of Air Mass Flow Sensor in Absence of Boost Pressure Sensor

摘要

In the move towards cleaner diesel emissions, the European On-Board Diagnostics (EOBD) legislation mandates monitoring of drift of air mass flow sensor. Drift of a sensor is defined as the phenomenon in which output signal slowly deviates independent of the measured property. Long-term drift usually indicates a slow degradation of sensor properties over a long period of time. Drift monitoring of the air mass flow sensor involves comparing the signal from the sensor with a reference signal under special operating conditions. Boost pressure sensor, which measures absolute intake manifold pressure and intake air temperature, is used to calculate the reference signal.