Abstract: Methods and systems are provided for a NOx sensor. In one example, a method includes heating a NOx sensor during a vehicle off in response to a cumulative heat energy applied to the NOx.

Abstract: Methods and systems are provided for a NOx sensor. In one example, a method includes heating a NOx sensor during a vehicle off in response to a cumulative heat energy applied to the NOx.

Abstract: Methods and systems for operating an engine that includes a controller and a NOx sensor are described. In one example, output of the NOx sensor is selectively made available to software modules within the controller when an offset in NOx sensor output is not expected. If the offset in NOx sensor output is expected, the NOx sensor output may not be made available to the software modules.

Abstract: Methods and systems for operating an engine that includes a controller and a NOx sensor are described. In one example, output of the NOx sensor is selectively made available to software modules within the controller when an offset in NOx sensor output is not expected. If the offset in NOx sensor output is expected, the NOx sensor output may not be made available to the software modules.

Abstract: A method for operating a turbocharged engine is disclosed. In one example, during a first condition an engine operation is adjusted in response to a turbocharger expansion ratio exceeding a first limit and during a second condition an engine operation is adjusted in response to the turbocharger expansion ratio exceeding a second limit that differs from the first limit. Degradation of the engine may be reduced under some engine operating conditions by adjusting engine operation in response to the turbocharger expansion ratio.

Abstract: Systems and methods for detecting ammonia slip in an exhaust system based upon transient NOx sensor responses are described. In one example method, an exhaust system allocates tailpipe NOx sensor output to NOx and NH3 levels responsive to the transient sensors using a segment length method that processes the transient signals based on the total segment lengths calculated within a window. A ratio of segment lengths relative to a threshold is determined for a measured and expected NOx rate of change downstream of an SCR that is further used to determine a probability of NOx and NH3 based on the measured sensor activities, and a controller is included to adjust one or more parameters based on the allocation and changes of sensor output.

Abstract: The systems and method described above in the present disclosure allow for regeneration of a diesel particulate filter while a vehicle is in stationary power take-off mode. Described is a method of: during select power take-off conditions, reducing an EGR rate responsive to an indication to regenerate a diesel particulate filter.

Abstract: A method for controlling combustion in an engine is provided. The method comprises under a first condition, adjusting an EGR amount of a total cylinder charge in response to engine out NOx levels being below a first threshold. In this way, NOx levels may be used as feedback to control combustion stability.

Abstract: A method for operating a turbocharged engine is disclosed. In one example, during a first condition an engine operation is adjusted in response to a turbocharger expansion ratio exceeding a first limit and during a second condition an engine operation is adjusted in response to the turbocharger expansion ratio exceeding a second limit that differs from the first limit. Degradation of the engine may be reduced under some engine operating conditions by adjusting engine operation in response to the turbocharger expansion ratio.

Abstract: A method for operating a turbocharged engine is disclosed. In one example, during a first condition an engine operation is adjusted in response to a turbocharger expansion ratio exceeding a first limit and during a second condition an engine operation is adjusted in response to the turbocharger expansion ratio exceeding a second limit that differs from the first limit. Degradation of the engine may be reduced under some engine operating conditions by adjusting engine operation in response to the turbocharger expansion ratio.

Abstract: The systems and method described above in the present disclosure allow for regeneration of a diesel particulate filter while a vehicle is in stationary power take-off mode. Described is a method of: during select power take-off conditions, reducing an EGR rate responsive to an indication to regenerate a diesel particulate filter.

Abstract: Systems and methods for detecting ammonia slip in an exhaust system based upon transient NOx sensor responses are described. In one example method, an exhaust system allocates tailpipe NOx sensor output to NOx and NH3 levels responsive to the transient sensors using a segment length method that processes the transient signals based on the total segment lengths calculated within a window. A ratio of segment lengths relative to a threshold is determined for a measured and expected NOx rate of change downstream of an SCR that is further used to determine a probability of NOx and NH3 based on the measured sensor activities, and a controller is included to adjust one or more parameters based on the allocation and changes of sensor output.

Abstract: A method for operating a turbocharged engine is disclosed. In one example, an engine operation is adjusted in response to a turbocharger expansion ratio. Degradation of the engine may be reduced under some engine operating conditions by adjusting engine operation in response to the turbocharger expansion ratio.

Abstract: A method for operating a turbocharged engine is disclosed. In one example, during a first condition an engine operation is adjusted in response to a turbocharger expansion ratio exceeding a first limit and during a second condition an engine operation is adjusted in response to the turbocharger expansion ratio exceeding a second limit that differs from the first limit. Degradation of the engine may be reduced under some engine operating conditions by adjusting engine operation in response to the turbocharger expansion ratio.

Abstract: A method for controlling combustion in an engine is provided. The method comprises under a first condition, adjusting an EGR amount of a total cylinder charge in response to engine out NOx levels being below a first threshold. In this way, NOx levels may be used as feedback to control combustion stability.

Abstract: A method for operating a turbocharged engine is disclosed. In one example, an engine operation is adjusted in response to a turbocharger expansion ratio. Degradation of the engine may be reduced under some engine operating conditions by adjusting engine operation in response to the turbocharger expansion ratio.

Abstract: A fuel control system for delivering gaseous fuel from a source through an air/fuel mixture to a gas-operated engine that includes at least one sensor for operative coupling to the engine to provide at least one electronic sensor signal responsive to engine operating conditions. An electronic control unit is responsive to the sensor signal(s) for providing a fuel control signal indicative of a desired quantity of fuel to be delivered to the engine. A pressure regulator, for disposition between the fuel source and the fuel/air mixture, is responsive to the fuel control signal for controlling delivery of gaseous fuel to the mixer. The pressure regulator includes a housing having an inlet for connection to the fuel source and an outlet for connection to the mixer. A valve is disposed within the housing and biased toward closure by a primary pressure regulating spring for controlling flow of fuel from the inlet to the outlet.