Diagnostics for Diesel Particulate Filters

This paper presents some of the challenges involved in diagnosing leaks in diesel particulate filters (DPFs). It concentrates on diagnosis with a pressure sensor. It is argued that not all failure modes can be detected by such a sensor, and that this method of diagnosis has far-reaching implications on the monitor completion frequency. Via an error analysis of commercially available sensors we argue that there is little to no separation between healthy and damaged particulate filters. The challenges are illustrated with straightforward analytical calculations.