An automatic transmission includes an oil temperature detecting unit configured to detect an oil temperature of the hydraulic oil, and a controller configured to perform the control of the speed ratio on a basis of the oil temperature obtained from the oil temperature detecting unit. The controller is configured such that if the controller has failed to obtain the oil temperature from the oil temperature detecting unit, the controller outputs a command to restrict an output from the driving force source, and such that if the controller has obtained the oil temperature from the oil temperature detecting unit again, the controller gradually cancels the command to restrict the output from the driving force source.

A shift range is selected based on a vehicle speed or acceleration of a vehicle and a shift range kept by a drive unit at the time when it is determined that there is a malfunction in shift sensors. Thus, it is possible to avoid a disabled self-propelled state resulting from a change into a neutral range through a fail-safe operation and keep limp home running.

Methods and systems are provided for operating a driveline of a hybrid vehicle that includes an internal combustion engine, an electric machine, and a transmission are described. In one example, the engine is started and coupled to the driveline via closing a clutch of a dual clutch transmission. Speed of the engine and clutch pressure are controlled to reduce driveline torque disturbances and provide a desired wheel torque.

Methods and systems are provided for launching a vehicle in an electric-only mode of operation. In one example, a driveline operating method comprises engaging a parking pawl to an output shaft of a dual clutch transmission in response to a request to engine a vehicle into a parked state, and disengaging the parking pawl via rotating an engine via an integrated starter/generator in response to a request to propel the vehicle solely via power of an electric machine positioned downstream of the dual clutch transmission. In this way, the vehicle may be launched in the electric-only mode without activating the engine in a fueled mode of operation and then deactivating the engine, which may increase vehicle operator satisfaction and which may improve fuel economy.

Methods and systems are provided for operating a driveline of a hybrid vehicle powertrain, where the driveline includes an electric machine downstream of a dual clutch transmission, which is downstream of an engine. In one example, a method comprises communicating from a transmission, a torque to accelerate transmission components from a first speed to a second speed with first and second clutches of a dual transmission open, the communicating performed while an electric machine coupled to the dual clutch transmission at a location downstream of the dual clutch transmission is providing torque to propel a vehicle. In this way, wheel speed may remain substantially constant while the transmission is shifted and the engine is stopped.

Methods and systems are provided for controlling clutch capacity in a hybrid electric vehicle. In one example, a method includes adjusting values of a transfer function of a clutch of a dual clutch transmission in response to an operating condition of an engine and/or operating condition of an integrated starter/generator coupled to the engine while a vehicle is propelled via an electric machine coupled to the dual clutch transmission, and maintaining a driver demand wheel torque at vehicle wheels via adjusting torque of the electric machine in response to the operating condition of the engine and/or operating condition of the integrated starter generator. In this way the method may apply pressure to one of the clutches where engine speed is independently controlled to maintain positive or negative slip, thus enabling adaptation of positive and negative clutch transfer functions, which may improve driveline operation and shift quality.

Methods and systems are provided for entering into a parked state in a hybrid electric vehicle that includes a dual clutch transmission. In one example, a driveline operating method comprises in response to a first condition, engaging a first gear and engaging a second gear of a dual clutch transmission in response to a request to enter a vehicle park state where an output of a transmission is held from rotating, and in response to a second condition, engaging a third gear and engaging a fourth gear of a dual clutch transmission in response to a request to enter a vehicle park state. In this way, a park state may be entered into without the use of a park pawl, which may reduce costs associated with the vehicle and which may prevent issues associated with degradation of the park pawl.

Methods and systems are provided for adjusting clutch pressures and electric machine torques as a function of a stability metric threshold(s) in order to balance performance and charging of an onboard energy storage device. In one example, a method comprises during an upshift of a transmission from a first gear to a second gear, adjusting a clutch pressure of the transmission to adjust slippage of a clutch in response to a vehicle stability control parameter exceeding a threshold. In this way, torque delivered to a transmission output shaft may be reduced, which may increase vehicle stability.

A method of operating a vehicle includes measuring a transmission output torque, measuring impeller and turbine speeds, estimating a transmission component torque, and adjusting an engine torque to avoid overstressing a transmission component such as a gear. The method does not rely on an accurate estimate of engine torque. Furthermore, the method does not rely on a fixed transmission torque rating in each gear ratio.

A method of protecting a multi-function drive axle system from damage, comprising the steps of: determining the axle torque and speed from sensors positioned on the multi-function drive axle system; using the axle torque and speed to approximate damage values for the driveline of the multi-function drive axle system; comparing the approximated values of driveline damage with driveline damage durability targets; identifying if the approximated values of driveline damage exceed the driveline damage durability targets; and limiting the engine torque and/or speed to produce an axle torque and speed corresponding to driveline damage values that do not exceed the driveline damage durability targets.