Regeneration of diesel engine particulate filter only above low fuel levels

Abstract

A filter used to remove particulates from a diesel engine exhaust is regenerated by increasing the exhaust temperature to achieve burn off of the accumulated particulates. Regeneration of the filter is inhibited when the sensed level of fuel in a diesel fuel tank for the engine falls below a first threshold level. Optionally, filter regeneration may be initiated when the sensed fuel level is between the first threshold and a higher threshold, and the load level of particulates accumulated in said filter is above a preselected, relatively high load level. Increase of the exhaust temperature to achieve burn off may be achieved by a variety of techniques, including throttling the intake of said engine, reducing the oxygen content in the exhaust gases delivered to said engine, closing an EGR valve of said engine, or performing post injection of fuel in the engine's combustion cylinders.