Abstract: Methods and systems are provided for controlling a vehicle system including an engine that is selectively shut-down during engine idle-stop conditions, the vehicle system further including a hydraulically actuated transmission component. One example method comprises, during an idle-stop engine shut-down, adjusting a hydraulic actuation of the transmission component to adjust drag torque on the engine to stop the engine.

Abstract: Methods and systems are provided for controlling a vehicle system including an engine that is selectively shut-down during engine idle-stop conditions, the vehicle system further including a hydraulically actuated transmission component. One example method comprises, during an idle-stop engine shut-down, adjusting a hydraulic actuation of the transmission component to adjust drag torque on the engine to stop the engine.

Abstract: Methods and systems are provided for controlling a vehicle system including an engine that is selectively shut-down during engine idle-stop conditions, the vehicle system further including a hydraulically actuated transmission component. One example method comprises, during an idle-stop engine shut-down, adjusting a hydraulic actuation of the transmission component to adjust drag torque on the engine to stop the engine.

Abstract: A controller and a control strategy for a hybrid electric vehicle having a traction motor between an engine and an automatic transmission include maintaining a bypass clutch of a torque converter in an engaged position and applying a motor torque from a traction motor to the torque converter such that slip of the torque converter does not otherwise reach zero while the bypass clutch is maintained in the engaged position.

Abstract: Systems and methods for assisted direct start control are provided. An example method varies engine torque, forward clutch engagement pressure, and wheel brake pressure during a vehicle launch responsive to longitudinal vehicle grade to improve launch performance.

Abstract: Methods and systems for controlling a vehicle powertrain that may be automatically stopped and started are presented. In one example, a method adjusts a position of a transmission clutch in response to battery current during engine cranking. The method may reduce clutch wear and improve vehicle launch from a stop.

Abstract: A control system including a method and apparatus for operating a hybrid vehicle. A disconnect clutch selectively separates an electric machine from a combustion engine. If a wide open throttle or high torque command is requested and the combustion engine is shut down, a 12 volt starter may be used to start the combustion engine while disconnected from the electric machine and all of the electric machine torque available may be used for traction.

Abstract: A control system including a method and apparatus for operating a hybrid vehicle. A disconnect clutch selectively separates an electric machine from a combustion engine. If a wide open throttle or high torque command is requested and the combustion engine is shut down, a 12 volt starter may be used to start the combustion engine while disconnected from the electric machine and all of the electric machine torque available may be used for traction.

Abstract: Systems for managing downshifts in hybrid-electric vehicles are disclosed. The systems include a multispeed transmission, an internal combustion engine selectively coupled to the multispeed transmission, an electric motor coupled to the multispeed transmission, and an electronic control unit. The electronic control unit is programmed to evaluate a torque demand, start the internal combustion engine, and pre-stage a downshift shift sequence by partially disengaging a second shift clutch and partially engaging a first shift clutch. The electronic control unit is also programmed to interrupt the downshift shift sequence until a pre-determined torque supplemental event occurs and later complete the downshift shift sequence by modifying the hydraulic pressure through the valve body to completely disengage a second gear set from the input shaft with the second shift clutch and completely engage a first gear set and the input shaft with the first shift clutch.

Abstract: Systems for managing downshifts in hybrid-electric vehicles are disclosed. The systems include a multispeed transmission, an internal combustion engine selectively coupled to the multispeed transmission, an electric motor coupled to the multispeed transmission, and an electronic control unit. The electronic control unit is programmed to evaluate a torque demand, start the internal combustion engine, and pre-stage a downshift shift sequence by partially disengaging a second shift clutch and partially engaging a first shift clutch. The electronic control unit is also programmed to interrupt the downshift shift sequence until a pre-determined torque supplemental event occurs and later complete the downshift shift sequence by modifying the hydraulic pressure through the valve body to completely disengage a second gear set from the input shaft with the second shift clutch and completely engage a first gear set and the input shaft with the first shift clutch.

Abstract: Methods and systems are provided for controlling a vehicle engine coupled to a stepped-gear-ratio transmission. One example method comprises, in response to a first vehicle moving condition, shutting down the engine and at least partially disengaging the transmission while the vehicle is moving; and during a subsequent restart, while the vehicle is moving, starting the engine using starter motor assistance and adjusting a degree of engagement of a transmission clutch to adjust a torque transmitted to a wheel of the vehicle.

Abstract: An apparatus and method for altering the drivability of a vehicle so as to alert a driver of the vehicle of a potentially hazardous condition. The vehicle has at least one sensor configured to detect the potentially hazardous potential. Additionally, the vehicle has a control system for directing a transmission of the vehicle to perform a transmission operation that catches the driver's attention by generating an acceleration or deceleration. The transmission operation is preferably an upshift, a downshift, an unlocking of a torque converter lockup clutch or a locking of the lockup clutch. In one embodiment, the control system directs the transmission to perform more than one transmission operation, the transmission operations defining a transmission operation cycle. In a preferred embodiment, more than one transmission operation cycle is performed.

Abstract: An apparatus and method for altering the drivability of a vehicle so as to alert a driver of the vehicle of a potentially hazardous condition. The vehicle has at least one sensor configured to detect the potentially hazardous potential. Additionally, the vehicle has a control system for directing a transmission of the vehicle to perform a transmission operation that catches the driver's attention by generating an acceleration or deceleration. The transmission operation is preferably an upshift, a downshift, an unlocking of a torque converter lockup clutch or a locking of the lockup clutch. In one embodiment, the control system directs the transmission to perform more than one transmission operation, the transmission operations defining a transmission operation cycle. In a preferred embodiment, more than one transmission operation cycle is performed.

Abstract: Methods and systems for controlling a vehicle powertrain that may be automatically stopped and started are presented. In one example, a method adjusts a position of a transmission clutch in response to battery current during engine cranking The method may reduce clutch wear and improve vehicle launch from a stop.

Abstract: An example method of operation comprises, selectively shutting down engine operation responsive to operating conditions and without receiving an engine shutdown request from the operator, maintaining the automatic transmission in gear during the shutdown, and during an engine restart from the shutdown condition, and with the transmission in gear, transmitting reduced torque to the transmission. For example, slippage of a forward clutch of the transmission may be used to enable the transmission to remain in gear, yet reduce torque transmitted to the vehicle wheels.

Abstract: Methods and systems for controlling a vehicle powertrain that may be automatically stopped and started are presented. In one example, a method adjusts a position of a transmission clutch in response to battery current during engine cranking. The method may reduce clutch wear and improve vehicle launch from a stop.

Abstract: A method of controlling a launch clutch during an engine restart event commands a positive torque capacity before the engine reaches idle speed. Early application of the launch clutch reduces the time delay between brake pedal release and vehicle acceleration. To avoid excessive drag on the engine during the restart event, the torque capacity is adjusted using closed loop control. A controller calculates a maximum rate of change of torque capacity based on measured engine speed and an engine acceleration and does not increase the commanded torque capacity faster than the calculated rate. In some circumstances the maximum rate of change may be negative, resulting in a reduction in commanded torque capacity.

Abstract: A method of controlling a launch clutch during an engine restart event commands a positive torque capacity before the engine reaches idle speed. Early application of the launch clutch reduces the time delay between brake pedal release and vehicle acceleration. To avoid excessive drag on the engine during the restart event, the torque capacity is adjusted using closed loop control. A controller calculates a maximum rate of change of torque capacity based on measured engine speed and an engine acceleration and does not increase the commanded torque capacity faster than the calculated rate. In some circumstances the maximum rate of change may be negative, resulting in a reduction in commanded torque capacity.

Abstract: Methods and systems are provided for controlling a vehicle system including a selectively shut-down engine, a torque converter and a torque converter lock-up clutch. One example method comprises, during an idle-stop engine shut-down, restricting flow of transmission fluid out of the torque converter, and adjusting engagement of the torque converter lock-up clutch to adjust a drag torque on the engine to stop the engine.

Abstract: A vehicle system and a method for calculating a vehicle mass is provided. In at least one embodiment, the system and the method measure current consumed by an electric machine of the vehicle to calculate vehicle mass. A controller of the vehicle uses the calculated mass to control operation of the vehicle, for example a four wheel drive, transmission, stability control, or brake system of the vehicle. A GPS and tire speed sensor system may be incorporated to detect the presence of a towed object, for example a trailer, and to further adjust operation of the vehicle.