Patent ID: 8281571

Claim:
A method to regenerate a diesel oxidation catalyst in an exhaust system with a fuel doser for normal and transient vehicle travel; said vehicle equipped with an electronically controlled compression ignition engine with an electronic control unit having memory and for receiving data signals from remote senor indicative of vehicle operating conditions; determining exhaust gas flow temperature at the diesel oxidation catalyst inlet; determining whether the exhaust gas temperature at the diesel oxidation catalyst inlet exceeds a first predetermined temperature value for a first predetermined period of time; dosing the exhaust system at the diesel oxidation catalyst inlet with a quantity of fuel based upon the exhaust gas flow temperature to regenerate a diesel particulate filter; determining whether the exhaust gas temperature at the diesel oxidation catalyst inlet exceeds a second, predetermined temperature for a second predetermined period of time, the second predetermined temperature being lower than the first predetermined temperature; determining whether the exhaust temperature at the DOC inlet exceeds a second predetermined temperature for less than a second predetermined period of time, wherein if the temperature at the DOC inlet exceeds the second predetermined temperature for less than the second predetermined period of time, the method suspends regeneration and continues normal engine operation; dosing the exhaust system at the diesel oxidation catalyst inlet with a quantity of fuel for up to a second predetermined period of time.