Exhaust system implementing low-temperature regeneration strategy

Abstract

An exhaust control system for use with a combustion engine is disclosed. The exhaust control system may have an exhaust passage configured to receive a flow of exhaust from the combustion engine, a particulate filter located within the exhaust passage, and an oxidation catalyst located upstream of the filter. The oxidation catalyst may be configured to promote regeneration of the particulate filter and may have an activation temperature range. The exhaust control system may also have a heating device located to selectively warm the oxidation catalyst to within the activation temperature range, and a controller in communication with the combustion engine and the heating device. The controller may be configured to detect a loading of the particulate filter exceeding a first loaded threshold amount, and to detect a low temperature condition of the combustion engine. The controller may further be configured to activate the heating device to warm the oxidation catalyst when the loading of the particulate filter exceeds the first loaded threshold amount during the low temperature condition and until the loading of the particulate filter is reduced below a second loaded threshold amount.