A method includes operating a spark ignition engine and flowing low pressure exhaust gas recirculation (EGR) from an exhaust to an inlet of the spark ignition engine. The method includes interpreting a parameter affecting an operation of the spark ignition engine, and determining a knock index value in response to the parameter. The method further includes reducing a likelihood of engine knock in response to the knock index value exceeding a knock threshold value.

A method includes operating a spark ignition engine and flowing low pressure exhaust gas recirculation (EGR) from an exhaust to an inlet of the spark ignition engine. The method includes interpreting a parameter affecting an operation of the spark ignition engine, and determining a knock index value in response to the parameter. The method further includes reducing a likelihood of engine knock in response to the knock index value exceeding a knock threshold value.

Methods and systems are provided for carrying out on-board diagnostics of a plurality of components of an exhaust heat exchange system. In one example, degradation of one or more of a heat exchanger and a coolant system fluidically coupled to the heat exchanger may be detected based on a first temperature estimated upstream of the heat exchanger, a second temperature sensor estimated downstream of the heat exchanger, a coolant temperature, and a pressure estimated upstream of the heat exchanger. Also, degradation of a diverter valve of the heat exchange system may be detected based on inputs of a position sensor coupled to the diverter valve.

Methods and systems are provided for carrying out on-board diagnostics of a plurality of components of an exhaust heat exchange system. In one example, degradation of one or more of a heat exchanger and a coolant system fluidically coupled to the heat exchanger may be detected based on a first temperature estimated upstream of the heat exchanger, a second temperature sensor estimated downstream of the heat exchanger, a coolant temperature, and a pressure estimated upstream of the heat exchanger. Also, degradation of a diverter valve of the heat exchange system may be detected based on inputs of a position sensor coupled to the diverter valve.

A method and apparatus for regenerating a Lean NOx Trap in an internal combustion engine is disclosed. The internal combustion engine includes a Lean NOx Trap, a turbocharger having a turbine. An electronic control unit is configured to execute a regeneration event of the Lean NOx Trap, and regulate a position of an actuator affecting a rotating speed of the turbine using a closed-loop control strategy of an air pressure into an intake duct downstream of a compressor of the turbocharger and upstream of a throttle valve during the execution of the regeneration event.

One exemplary embodiment is a system comprising a multi-fuel engine structured to selectably combust varying proportions of a first type of fuel and a second type of fuel, and an electronic control system structured to control the provision of at least one of the first type of fuel and the second type of fuel to the engine using a multi-factor cost optimization. The multi-factor cost optimization may account for a plurality of factors including one or more environment factors, location factors, mission factors, warranty factors, operator-specified factors and/or fleet-specified factors.

A heat exchanger for a vehicle includes a housing having an interior space through which exhaust gas recirculation (EGR) gas passes, a first heat exchange core disposed in the interior space of the housing, a second heat exchange core disposed in the interior space of the housing and disposed on a downstream side of the first heat exchange core, and a bypass valve configured to allow the EGR gas to selectively detour the second heat exchange core.

Systems and methods for controlling operation of dual fuel internal combustion engines in response to cylinder pressure based determinations are disclosed. The techniques control fueling contributions from a first fuel source and a second fuel source to achieve desired operational outcomes in response to the cylinder pressure based determinations.

Systems and methods for controlling operation of dual fuel internal combustion engines in response to cylinder pressure based determinations are disclosed. The techniques control fueling contributions from a first fuel source and a second fuel source to achieve desired operational outcomes in response to the cylinder pressure based determinations.

A method of operating an internal combustion engine, and more particularly a fuel injector is disclosed. The fuel injector is commanded to inject a fuel requested quantity. The fuel requested quantity is adjusted by closed-loop for controlling an engine speed to match a target value thereof. A value of a first parameter indicative of an amount of electrical energy supplied to an electric battery by an electric generator coupled to the internal combustion engine is measured. A value of a voltage generated by the electric battery and a value of the engine speed are measured. A reference value of the fuel requested quantity is calculated on the basis of the voltage value, the engine speed value and the value of the first parameter. A difference between the value of the adjusted fuel requested quantity and the reference value is calculated and used to control the internal combustion engine.