Systems and methods for controlling an engine based on aftertreatment system characteristics

A system comprising:

• a sensor structured to provide a sensor signal indicative of an exhaust gas characteristic;
• an aftertreatment system control circuit coupled to the sensor, the aftertreatment system control circuit structured to:
• receive the sensor signal,
• determine an aftertreatment system characteristic as a function of the exhaust gas characteristic,
• determine an acceptable input value as a function of the aftertreatment system characteristic, and
• send a command signal indicative of the acceptable input value;
• and
• an engine control circuit coupled to the aftertreatment system control circuit, the engine circuit structured to:
• receive the command signal, and to control at least one of a fuel system and an air handling actuator to achieve the acceptable input value,
• determine a correction factor required to achieve the acceptable input value,
• compare the correction factor to a predetermined threshold, and
• generate a fault code when the correction factor exceeds the predetermined threshold.

A method comprising:

• receiving a signal from an aftertreatment sensor by an aftertreatment system control circuit, the signal indicative of an exhaust gas characteristic;
• determining, by the aftertreatment system control circuit, an aftertreatment system characteristic as a function of the exhaust gas characteristic;
• determining, by the aftertreatment system control circuit, an acceptable input value as a function of the aftertreatment system characteristic, the acceptable input value associated with a desired condition of exhaust gas exiting an engine and differing from the exhaust gas characteristic;
• communicating the acceptable input value to an engine control circuit;
• determining, by the engine control circuit, a correction factor to achieve the acceptable input value;
• controlling, by the engine control circuit, at least one of a fuel system and an air handling actuator to achieve the acceptable input value;
• comparing, by the aftertreatment system control circuit, the acceptable input value to a predetermined acceptable input threshold criteria;
• comparing, by the engine control circuit, the correction factor to a predetermined correction threshold;
• and
• generating, by the aftertreatment system control circuit, a fault code when the acceptable input value fails to meet the predetermined acceptable input threshold criteria or the correction factor exceeds the predetermined correction threshold.