Abstract: A system and method for controlling a vehicle powertrain having an internal combustion engine include determining a difference between a desired engine torque and a current engine torque, adjusting the difference based on a stored torque offset corresponding to a current engine speed, and controlling the engine to produce a torque corresponding to the adjusted torque difference. The stored torque offset is adjusted when the engine is operating in a predetermined engine speed range based on a steady-state difference between the desired and current engine torque to reduce the steady-state difference to zero. The adjusted torque difference may be limited by a maximum-engine-torque-available parameter and a minimum-engine-torque-available parameter, which is based on an operating temperature, such as the engine coolant temperature. The system and method may also include controlling spark to rapidly reduce current engine torque to the adjusted torque difference value.

Abstract: A method for selectively adjusting an amount of fuel to an engine in a vehicle is provided. The vehicle includes an electric machine operatively connected to the engine and capable of controlling a speed of the engine. The method includes providing an amount of fuel to the engine based at least in part on a desired output of the engine, which is based at least in part on a driver input. The electric machine is commanded to control the engine speed based at least in part on the driver input. An output error of the engine is determined based at least in part on the command to the electric machine. The amount of fuel provided to the engine is adjusted when at least one predetermined condition is met, including the output error of the engine being greater than a predetermined amount.

Abstract: A method for operating a vehicle to reduce exhaust emissions is provided. The vehicle includes an engine, a motor, a battery for operating the motor, and a catalyst for reducing exhaust gas emissions. The vehicle is operated in a first mode when at least one predetermined condition is met. The first mode includes providing at least some of the desired vehicle output power with the motor. The engine is operated to quickly increase the temperature of the catalyst when the output power from the battery is within a first predetermined range. When the output power of the battery is outside the first predetermined range, the operation of the engine is adjusted to drive battery operation into the first predetermined range. When the at least one predetermined condition is not met, the vehicle is operated in a second mode based at least partly on driver demand and battery requirements.

Abstract: A method for controlling fuel injection during engine startup in a hybrid electric vehicle. The hybrid electric vehicle includes an engine, a power source, an electrical machine, and a control module. The method includes the steps of driving the engine with the electrical machine, determining whether the engine is at a target state, selecting a cylinder for fuel injection, calculating an amount of fuel to provide to the cylinder, injecting the amount of fuel, and repeating the selecting, calculating, and injecting steps for another cylinder for a predetermined number of iterations.

Abstract: A vehicle and method are provided that determine a misfire torque limit for an engine in the vehicle. The vehicle includes an electric machine operable to provide torque to the engine. The method includes commanding the engine to operate at a predetermined torque and a predetermined speed, thereby putting the engine in an idle state. An output torque of the engine is then determined while the engine is in the idle state. A torque offset, defined as the difference between the torque command and the determined engine output torque, is also determined. The misfire torque limit for the engine is then determined based at least in part on the torque offset.

Abstract: A method for operating a vehicle to reduce exhaust emissions is provided. The vehicle includes an engine, a motor, a battery for operating the motor, and a catalyst for reducing exhaust gas emissions. The vehicle is operated in a first mode when at least one predetermined condition is met. The first mode includes providing at least some of the desired vehicle output power with the motor. The engine is operated to quickly increase the temperature of the catalyst when the output power from the battery is within a first predetermined range. When the output power of the battery is outside the first predetermined range, the operation of the engine is adjusted to drive battery operation into the first predetermined range. When the at least one predetermined condition is not met, the vehicle is operated in a second mode based at least partly on driver demand and battery requirements.

Abstract: A method for controlling fuel injection during engine startup in a hybrid electric vehicle. The hybrid electric vehicle includes an engine, a power source, an electrical machine, and a control module. The method includes the steps of driving the engine with the electrical machine, determining whether the engine is at a target state, selecting a cylinder for fuel injection, calculating an amount of fuel to provide to the cylinder, injecting the amount of fuel, and repeating the selecting, calculating, and injecting steps for another cylinder for a predetermined number of iterations.

Abstract: A vehicle and method are provided that determine a misfire torque limit for an engine in the vehicle. The vehicle includes an electric machine operable to provide torque to the engine. The method includes commanding the engine to operate at a predetermined torque and a predetermined speed, thereby putting the engine in an idle state. An output torque of the engine is then determined while the engine is in the idle state. A torque offset, defined as the difference between the torque command and the determined engine output torque, is also determined. The misfire torque limit for the engine is then determined based at least in part on the torque offset.

Abstract: A method for selectively adjusting an amount of fuel to an engine in a vehicle is provided. The vehicle includes an electric machine operatively connected to the engine and capable of controlling a speed of the engine. The method includes providing an amount of fuel to the engine based at least in part on a desired output of the engine, which is based at least in part on a driver input. The electric machine is commanded to control the engine speed based at least in part on the driver input. An output error of the engine is determined based at least in part on the command to the electric machine. The amount of fuel provided to the engine is adjusted when at least one predetermined condition is met, including the output error of the engine being greater than a predetermined amount.