Abstract: Systems and methods for starting an engine that is incorporated into a hybrid vehicle driveline are described. In one example, a torque converter clutch is fully opened if a threshold amount has transpired after a request for torque converter clutch slip is requested but not delivered. Further, the torque converter clutch may be fully opened if a commanded torque converter clutch torque capacity is less than a threshold torque capacity.

Abstract: A method for operating a vehicle that includes a driveline disconnect clutch is described. In one example, the method includes adjusting a pressure of the driveline disconnect clutch as a function of an engine pull-up torque minus a driver demand torque when the pressure of the driveline disconnect clutch is between a torque stroke pressure and a hydraulic stroke pressure.

Abstract: A system and method for controlling a hybrid vehicle having an engine and a traction motor include operating the engine at an operating point selected based on system efficiency, operating the electric machine to provide an electric machine torque responsive to a difference between a driver demand torque and the engine torque associated with the operating point, and limiting a rate of change of the electric machine torque in response to a rate of change of the driver demand torque. The electric machine torque rate limit may vary continuously responsive to the rate of change of driver demand torque and whether the driver demand torque is increasing or decreasing.

Abstract: Systems and methods for operating a hybrid powertrain or driveline that includes an engine and an integrated starter/generator are described. In one example, rotation of an automatically stopped engine may be inhibited when engine braking is requested so that the engine may not be rotated without providing a desired outcome.

Abstract: A vehicle includes a torque converter bypass clutch, a wheel, a generator, and a controller. The torque converter bypass clutch is disposed between the wheel and the electric machine. The controller is programmed to, responsive to slip of the clutch exceeding a threshold during regenerative braking, energize the electric machine such that a torque being transferred from the wheel to the electric machine increases at a first rate and increase clutch pressure to decrease the slip. The controller is further programmed to, responsive to the slip decreasing to less than the threshold during the regenerative braking, adjust electric machine energization such the that torque being transferred from the wheel to the electric machine increases at a second rate that is greater than the first rate.

Abstract: A method for operating a vehicle that includes a driveline disconnect clutch is described. In one example, the method includes adjusting a pressure of the driveline disconnect clutch as a function of an engine pull-up torque minus a driver demand torque when the pressure of the driveline disconnect clutch is between a torque stroke pressure and a hydraulic stroke pressure.

Abstract: Systems and methods for operating a hybrid powertrain or driveline that includes an engine and an integrated starter/generator are described. In one example, the integrated starter/generator may rotate a torque converter during a vehicle activation process if a vehicle soak time exceeds a threshold. The integrated starter/generator may not rotate the torque converter during a vehicle activation process if a vehicle soak time is less than the threshold.

Abstract: Systems and methods for operating a hybrid powertrain or driveline that includes an engine and an integrated starter/generator are described. In one example, rotation of an automatically stopped engine may be inhibited when engine braking is requested so that the engine may not be rotated without providing a desired outcome.

Abstract: Systems and methods for starting an engine that is incorporated into a hybrid vehicle driveline are described. In one example, a torque converter clutch is fully opened if a threshold amount has transpired after a request for torque converter clutch slip is requested but not delivered. Further, the torque converter clutch may be fully opened if a commanded torque converter clutch torque capacity is less than a threshold torque capacity.

Abstract: A vehicle includes a torque converter bypass clutch, a wheel, a generator, and a controller. The torque converter bypass clutch is disposed between the wheel and the electric machine. The controller is programmed to, responsive to slip of the clutch exceeding a threshold during regenerative braking, energize the electric machine such that a torque being transferred from the wheel to the electric machine increases at a first rate and increase clutch pressure to decrease the slip. The controller is further programmed to, responsive to the slip decreasing to less than the threshold during the regenerative braking, adjust electric machine energization such the that torque being transferred from the wheel to the electric machine increases at a second rate that is greater than the first rate.

Abstract: Systems and methods for operating a hybrid powertrain or driveline that includes an engine and an integrated starter/generator are described. In one example, the integrated starter/generator may rotate a torque converter during a vehicle activation process if a vehicle soak time exceeds a threshold. The integrated starter/generator may not rotate the torque converter during a vehicle activation process if a vehicle soak time is less than the threshold.

Abstract: A vehicle includes and an engine, a motor, a transmission, and a controller. The transmission is configured is to receive power from the engine and the motor. The transmission is also configured to shift between gears based on a shift schedule. The controller is programmed to, in response to only the motor providing power to the transmission, adjust the shift schedule to narrow an operating speed range of the motor such that the motor speed maintains a peak range of an available motor power output.

Abstract: Systems and methods for operating a transmission of a hybrid powertrain that includes a motor/generator are described. The systems and methods may permit or inhibit transmission shifting in response to objects or conditions in a vehicles travel path. Transmission shifting is not permitted when conditions indicate the possibility of excessive transmission shifting.

Abstract: A vehicle includes a generator, a battery, a transmission, and a controller. The generator is configured to recharge the battery at a maximum power output when a generator speed is above a threshold speed. The transmission is configured to downshift during regenerative braking such that the generator speed is maintained above the threshold speed. The controller is programmed to, in response to a decrease in battery temperature corresponding to a decrease in generator speed required to maintain the maximum power output, decrease the threshold speed.

Abstract: A vehicle includes and an engine, a motor, a transmission, and a controller. The transmission is configured is to receive power from the engine and the motor. The transmission is also configured to shift between gears based on a shift schedule. The controller is programmed to, in response to only the motor providing power to the transmission, adjust the shift schedule to narrow an operating speed range of the motor such that the motor speed maintains a peak range of an available motor power output.

Abstract: A vehicle includes a generator, a battery, a transmission, and a controller. The generator is configured to recharge the battery at a maximum power output when a generator speed is above a threshold speed. The transmission is configured to downshift during regenerative braking such that the generator speed is maintained above the threshold speed. The controller is programmed to, in response to a decrease in battery temperature corresponding to a decrease in generator speed required to maintain the maximum power output, decrease the threshold speed.

Abstract: Systems and methods for operating a transmission of a hybrid powertrain that includes a motor/generator are described. The systems and methods may permit or inhibit transmission shifting in response to objects or conditions in a vehicles travel path. Transmission shifting is not permitted when conditions indicate the possibility of excessive transmission shifting.