Patent ID: 8959979
Filing Date: 2015-02-24
Classification: F01N,F02D,G01N,Y02T

Abstract:
1. A method for detecting a degraded dielectric particulate matter sensor, comprising: starting an engine with an engine temperature less than a dewpoint temperature; indicating degradation of said particulate matter sensor in response to a conductance of said particulate matter sensor staying below a threshold and lacking an impulse-like change as engine temperature increases past the dewpoint temperature; indicating that the particulate matter sensor is not degraded in response to the conductance rising above the threshold and including the impulse-like change, as the engine temperature increases past the dewpoint temperature, said sensor having two electrodes separated by a dielectric gap; and activating a heater of an oxygen sensor located in an exhaust path of said engine after said start and when said indicating degradation does not take place.