A vehicle, a vehicle powertrain system, a computer program product, and a method of controlling a vehicle in a manner to achieve enhanced driving performance. An example vehicle powertrain system includes one or more of a powertrain having an engine, a transmission, and a torque converter, and a control module to control the powertrain system. The control module is configured to conduct, in response to sensor data in connection with a detected current vehicle speed and a detected current transmission oil temperature, a vehicle powertrain analysis of the sensor data. The control module is to then control the powertrain in response to the vehicle powertrain analysis and an operating state of a lock-up clutch of the torque converter.

A CPU of a control device is configured to perform a specific cylinder fuel cutoff process of causing an internal combustion engine to operate such that supply of fuel to some cylinders out of a plurality of cylinders is stopped and supply of fuel to the other cylinders is maintained and a fastening force decreasing process of decreasing a fastening force of a lockup clutch of a torque converter. The CPU is configured to start the specific cylinder fuel cutoff process in a state in which the fastening force has been decreased through the fastening force decreasing process when the specific cylinder fuel cutoff process is performed in a state in which the internal combustion engine operates with a load.

The controller is programmed to perform first control that controls a driving force distributor such as to decrease a distribution rate upon satisfaction of a predetermined condition that a frequency of at least one rotation fluctuation of an output member of the drive system, a main drive wheel and a sub drive wheel is within a predetermined area, compared with the distribution rate upon non-satisfaction of the predetermined condition.

Methods and systems are provided for controlling and diagnosing a mechanical vehicle component. In one example, a method may include determining a vehicle speed and a plurality of clutch position settings at a diagnostic controller, and identifying unauthorized conditions based on these determinations. Further, the diagnostic controller may trigger an active fault state of the mechanical vehicle component in order to avoid unauthorized conditions that may lead to unwanted or unanticipated changes in vehicle motion.

A method and system for operating a vehicle that includes an automatic transmission with a torque converter clutch is described. In one example, the method includes predicting a time that the torque converter clutch will open so that stopping rotation of the engine may be requested before the torque converter clutch is opened. The stopping rotation of the engine is requested to conserve fuel.

Systems and methods for improving operation of a vehicle are presented. In one example, a controller may respond to a temperature of a catalyst to permit or temporarily inhibit a vehicle from moving. Engine load and engine emissions may be reduced by limiting vehicle motion until a catalyst temperature exceeds a threshold temperature.

Systems and control methods can provide for determining a TrnAin torque request from desired vehicle acceleration in a vehicle that utilizes a WTC architecture to allow for smooth transition between different transmission states, such as torque converter bypass clutch states and shifts between transmission gear ratios. The methods provide consistent and smooth vehicle acceleration profile during transmission state transitions. The methods also provide the ability to track the desired vehicle acceleration consistently from virtual driver demand sources, such as adaptive cruise control, autonomous vehicle, or remote parking, without allocating any additional resource to account for transmission state transitions. The proposed methods are applicable to any TC-based automatic transmission drivetrain, such as conventional powertrain, MHT, P4 HEV, or even BEV powertrains where the motor is located on the impeller side of a torque converter.

Methods and systems for operating a torque converter clutch of an automatic transmission are presented. In one non-limiting example, the torque converter clutch is closed to provide a threshold torque capacity during a vehicle launch. If an engine torque request is less than the threshold torque capacity, the torque converter clutch remains closed.

A vehicle includes friction brakes, an axle, and a controller. The axle has an electronic limited-slip differential that includes a variable torque capacity lockup clutch. The controller is programmed to, in response to a difference between desired and actual yaw rates exceeding a first threshold, increase the torque of the lockup clutch to decrease the difference between the desired and actual yaw rates. The controller is further programmed to, in response the difference between desired and actual yaw rates exceeding a second threshold that is greater than the first threshold, increase the torque of the friction brakes to decrease the difference between the desired and actual yaw rates.

Systems and methods for operating a hybrid powertrain that includes an engine and a motor/generator are described. The systems and methods adjust torque converter clutch opening responsive to whether or not a motor/generator is available to provide a negative torque to a driveline. Further, the motor/generator and the vehicle's engine are operated to provide a desired amount of driveline braking.