A vehicle includes an engine, electric machine, starter-generator, and a controller. The engine and electric machine are each configured to propel the vehicle. The starter-generator is coupled to the engine and is configured to adjust engine speed during an engine start-up event. The controller is programmed to, in response to engine speed increasing towards a target speed during an engine start-up event, generate a target drag torque with the starter-generator to reduce overshoot of the target engine speed.

A vehicle control device for controlling a vehicle with a frictional engagement element provided between a drive source and drive wheels includes a first determination unit configured to determine whether or not a signal of an inhibitor switch indicates a traveling position, a second determination unit configured to determine whether or not an oil path communicating with the frictional engagement element is in a drain state, a temperature estimation unit configured to estimate temperature of the frictional engagement element, and a temperature estimation prohibition unit configured to prohibit temperature estimation of the frictional engagement element by the temperature estimation unit when the signal of the inhibitor switch indicates the traveling position and the oil path is in the drain state.

Methods are provided for checking the actuating accuracy of a clutch arranged in a force flow between a fixable shaft and an electric machine of an electric or hybrid motor vehicle when at a standstill. One method includes: fixing the shaft, setting a defined setpoint torque on the clutch to be checked, continuously ramping up the electric machine up until the first slipping of the clutch, comparing the achieved torque of the electric machine with the setpoint torque preset on the clutch. Another method includes: fixing the shaft, ramping up the electric machine to a defined rotational speed, setting a defined setpoint torque on the clutch to be checked, comparing the torque of the electric machine needed to maintain a constant rotational speed with the setpoint torque set on the clutch.

Systems and methods for operating a driveline disconnect clutch of a hybrid vehicle are presented. In one example, the systems and methods may adjust a relationship (e.g., transfer function) between an amount of electric current that is supplied to a driveline disconnect clutch control valve and a commanded driveline disconnect clutch pressure.

Systems and methods for operating a driveline of a hybrid vehicle are presented. In one example, a boost phase of a procedure to close a driveline disconnect clutch may be cut short in response to an engine changing state from not rotating to rotating so that the engine may be restarted in an alternative way. The system and methods may also predict a degraded engine start from a low engine cranking speed or a long cranking time duration so that the engine may be started in an alternative way to increase a possibility of starting the engine and decrease the severity of degraded driveline disturbance.

Systems and methods for starting an engine of a hybrid vehicle are described. In one example, the method starts an engine according to vehicle conditions that are within a range that is defined by one or more thresholds. The thresholds may be adjusted based on a history of individual driving patterns.

A method and system of controlling an engine for vehicle interior heating is provided. The method includes performing a first engine control when the engine is not in an engine-on state for vehicle driving, to perform heating control for interior heating at a predetermined range of a reference coolant temperature. Additionally, the method includes performing a second engine control when the engine is in an engine-on state for vehicle driving, to prolong an engine-on time for vehicle driving by setting a minimum value of the range of the reference coolant temperature to a lower value and setting a maximum value of the range of the reference coolant temperature to a higher value and to determine a point of time of engine-off operation based on a real-time lock up time and an average lock up time of an engine clutch for vehicle driving.

A transmission is provided having a control module, an input member, an output member, four planetary gear sets, a plurality of interconnecting members, and a plurality of torque transmitting devices. Each of the planetary gear sets includes first, second and third members. The torque transmitting devices include clutches and brakes. The control module includes a control logic sequence for performing a coasting downshift of the transmission.

A hybrid electric vehicle includes an engine and an electric machine, both capable of providing propulsion power. A clutch is configured to selectively couple the engine to the electric machine. At times, the vehicle may be subject to excessive loads, such as a large amount of weight in the vehicle or the vehicle towing another object. At least one controller is programmed to engage the clutch and start the engine in response to a load of the vehicle exceeding a predetermined threshold and a release of the brake pedal while the vehicle is stopped and in drive. This increases available engine torque prior to vehicle launch in anticipation of an upcoming acceleration demand.

A vehicle includes an engine and an electric machine coupled to a transmission element. The electric machine is also selectively coupled with the engine by a clutch. The vehicle includes a belt integrated starter-generator (BISG) operatively coupled to the engine. An electronic controller includes one or more inputs adapted to receive a temperature measurement and a request to start the engine. The electronic controller is programmed to, in response to the one or more inputs receiving the request to start the engine and the temperature measurement less than a threshold temperature measurement, effect actuation of the electric machine and close the clutch to apply a first torque to the engine. The electronic controller is further programmed to, in response to an engine speed achieving an engine speed threshold, effect actuation of the BISG to apply a second torque to the engine.