Patent ID: 7991533

Claim:
A method of controlling reductant dosing level introduced to a selective catalytic reduction device implemented by a controller located within a vehicle, comprising: determining available reductant, based on data received from a sensor in communication with a reductant tank; determining a distance to a source of reductant, wherein said source of reductant includes a reductant refilling station, based on data received from one or more of the following: GPS, wireless towers and driver input; determining if said available reductant is less than a predetermined level; setting a reductant low limit flag and determining if a by-pass mode has been manually set if said available reductant is less than said predetermined level; implementing said by-pass mode if said by-pass mode has been manually set, with zero reductant dosing, and counting the number of times said by-pass mode with zero reductant dosing has been previously implemented by said controller; determining if the number of times previously in said by-pass mode exceeds a previously determined value; and if said number of times previously in said by-pass mode exceeds a previously determined value operating an engine in said vehicle under an engine calibration for low-engine out emissions.