Abstract: A method includes determining whether a urea refill event is detected, and clearing a quality accumulator value and clearing a latching abort command. The method includes determining whether urea fluid quality check abort conditions are met, and clearing the urea quality accumulator, latching the abort command, and exiting the reductant fluid quality check. In response to the abort conditions not being met, incrementing the urea quality accumulator according to an amount of urea being injected, and comparing the accumulated urea quantity to a low test threshold. The method includes, in response to the accumulated urea quantity being greater than the low test threshold, comparing the accumulated urea quantity to a high test threshold, and in response to the urea quantity being greater than the high test threshold, determining whether the a NOx exceedance is observed and clearing a urea quality error in response to the NOx exceedance not being observed.

Abstract: A method includes determining whether a urea refill event is detected, and clearing a quality accumulator value and clearing a latching abort command. The method includes determining whether urea fluid quality check abort conditions are met, and clearing the urea quality accumulator, latching the abort command, and exiting the reductant fluid quality check. In response to the abort conditions not being met, incrementing the urea quality accumulator according to an amount of urea being injected, and comparing the accumulated urea quantity to a low test threshold. The method includes, in response to the accumulated urea quantity being greater than the low test threshold, comparing the accumulated urea quantity to a high test threshold, and in response to the urea quantity being greater than the high test threshold, determining whether the a NOx exceedance is observed and clearing a urea quality error in response to the NOx exceedance not being observed.

Abstract: According to one embodiment, an apparatus for controlling the heating of diesel exhaust fluid (DEF) in a DEF delivery system includes a temperature comparison module that compares a difference between a sensed ambient air temperature and a sensed DEF tank temperature with a predetermined temperature difference threshold. Additionally, the apparatus includes a DEF heating status module that is configured to generate a DEF heating command according to (i) the sensed ambient air temperature if the difference between the sensed ambient air temperature and sensed DEF tank temperature is less than the predetermined temperature threshold; and (ii) the sensed DEF tank temperature if the difference between the sensed ambient air temperature and sensed DEF tank temperature is more than the predetermined temperature threshold. The apparatus also includes a DEF heating control module that is configured to control the heating of the DEF according to the DEF heating command.

Abstract: An apparatus for determining a deterioration of a NOx sensor response rate in an internal combustion engine system includes an engine control module configured to stop fueling to an internal combustion engine during motoring of the internal combustion engine. The apparatus also includes a signal monitoring module configured to monitor a NOx sensor signal after the engine control module stops fueling to the internal combustion engine during motoring of the engine and store NOx sensor signal data corresponding to the monitored NOx sensor signal. Additionally, the apparatus includes a time constant module that is configured to determine a time constant of the NOx sensor response after the engine control module stops fueling. The apparatus further includes a response rate deterioration module configured to determine a response rate deterioration value of the NOx sensor based at least partially on the determined time constant.

Abstract: Systems and methods for monitoring catalyst presence, reverse and damage in an aftertreatment device. The disclosed systems and methods involve calculating the heat capacity of the catalyst device based on information received from sensors for measuring temperatures at the inlet and outlet of the SCR device and the exhaust mass flow.

Abstract: According to one embodiment, an apparatus for controlling the heating of diesel exhaust fluid (DEF) in a DEF delivery system includes a temperature comparison module that compares a difference between a sensed ambient air temperature and a sensed DEF tank temperature with a predetermined temperature difference threshold. Additionally, the apparatus includes a DEF heating status module that is configured to generate a DEF heating command according to (i) the sensed ambient air temperature if the difference between the sensed ambient air temperature and sensed DEF tank temperature is less than the predetermined temperature threshold; and (ii) the sensed DEF tank temperature if the difference between the sensed ambient air temperature and sensed DEF tank temperature is more than the predetermined temperature threshold. The apparatus also includes a DEF heating control module that is configured to control the heating of the DEF according to the DEF heating command.

Abstract: In one embodiment, an apparatus for determining a deterioration of a NOx sensor response rate in an internal combustion engine system includes an engine control module configured to stop fueling to an internal combustion engine during motoring of the internal combustion engine. The apparatus also includes a signal monitoring module configured to monitor a NOx sensor signal after the engine control module stops fueling to the internal combustion engine during motoring of the engine and store NOx sensor signal data corresponding to the monitored NOx sensor signal. Additionally, the apparatus includes a time constant module that is configured to determine a time constant of the NOx sensor response after the engine control module stops fueling. The apparatus further includes a response rate deterioration module configured to determine a response rate deterioration value of the NOx sensor based at least partially on the determined time constant.

Abstract: Systems and methods for monitoring catalyst presence, reverse and damage in an aftertreatment device. The disclosed systems and methods involve calculating the heat capacity of the catalyst device based on information received from sensors for measuring temperatures at the inlet and outlet of the SCR device and the exhaust mass flow.