Patent ID: 8186146

Claim:
An after-treatment component detection system, comprising: an exhaust system configured to carry exhaust gases produced by a combustion engine away from the engine and configured to include an after-treatment component configured to remove one or more constituents of the exhaust gases; an upstream temperature sensor configured to measure temperature upstream from the after-treatment component; a downstream temperature sensor configured to measure temperature downstream from the after-treatment component; and a controller configured to: receive signals indicative of upstream temperature measurements from the upstream temperature sensor and signals indicative of downstream temperature measurements from the downstream temperature sensor; determine, from the received signals, an upstream rate of temperature change and a downstream rate of temperature change; determine, from the received signals, an absolute difference between the upstream temperature and the downstream temperature; compare the upstream rate of temperature change to the downstream rate of temperature change; and generate a fault if the upstream rate of temperature change and the downstream rate of temperature change differ by less than a predetermined amount, and the absolute difference between the upstream temperature and the downstream temperature is below a threshold value.