METHOD AND SYSTEM FOR VERIFYING THE OPERATION OF AN SCR CATALYST

摘要

A method and control system for a selective catalytic reduction (SCR) catalytic converter and an ammonia dosing module that stores ammonia in a selective catalyst reducing (SCR) catalyst and that depletes the ammonia level by discontinuing or reducing dosing. The control system also includes an SCR conversion efficiency module that determines an SCR efficiency. An SCR efficiency comparison module compares the SCR efficiency to an efficiency threshold and generates a fault indicator when the SCR efficiency is not above the efficiency threshold.