Method for detecting whether injector of selective catalytic reduction system in combustion engine of vehicle is clogged, involves continuously measuring pressure and/or energy characteristic parameter transmitted to pump by motor

摘要

The method involves continuously measuring pressure of a rotary positive-displacement pump driven by a motor i.e. brushless direct current motor and/or an energy characteristic parameter e.g. rotation speed, transmitted to the pump by the motor, by a controller. Profile of losses or fluctuations of pressure or the energy characteristic parameter is compared with a reference profile stored in a memory during normal operation of a selective catalytic reduction (SCR) system. Pulse width modulation signal is sent to the controller by an electronic control module.