Patent ID: 8640441
Filing Date: 2014-02-04
Classification: F01N,F02D,Y02T

Abstract:
1. A method of monitoring a differential pressure sensor of an exhaust gas aftertreatment system of a vehicle used to treat a flow of exhaust gas from an engine, the method comprising: sensing a learned value (n−1, n, n+1, n+2, etc.) of the differential pressure sensor for each after-run occurrence of the vehicle; calculating an absolute value of a rate of change between a current (n) learned value of the differential pressure sensor and a previous (n−1) learned value of the differential pressure sensor; comparing the absolute value of the rate of change of the learned values of the differential pressure sensor to a threshold pressure value to determine if the absolute value of the rate of change of the learned values is greater than the threshold pressure value or is less than the threshold pressure value; and signaling a fault in the differential pressure sensor when the absolute value of the rate of change of the learned values is greater than the threshold pressure value.