Patent ID: 7788911

Claim:
A system, comprising: an internal combustion engine operable to produce exhaust; an exhaust subsystem to receive the exhaust from the engine, the subsystem including an aftertreatment device; a temperature sensor positioned in the exhaust subsystem upstream from the aftertreatment device to sense temperature of exhaust gas entering the aftertreatment device; a controller responsive to the temperature sensor to time a duration temperature is less than a first value corresponding to adsorption of a substance including one or more of a hydrocarbon and H 2 O by the aftertreatment device and selectively decrease the duration for one or more time intervals the temperature is greater than a second value corresponding to desorption of the substance, the controller generating an output signal if the duration reaches a threshold indicative of an undesired adsorbed accumulation of the substance; and at least one engine control device responsive to the output signal to increase the temperature of the exhaust entering the aftertreatment device to cause the desorption of the substance.