Methods and systems for improving operation of a vehicle driveline that includes an engine and an automatic transmission with a torque converter are presented. In one non-limiting example, the engine may be stopped while a vehicle in which the engine operates is rolling. A transmission coupled to the engine may be shifted as the vehicle rolls so that vehicle response may be improved if a driver requests an increase of engine torque.

A transmission system avoids activation of a sailing functionality in a vehicle. The transmission system is configured for automatic gear-shifting in an automatic mode and manual gear-shifting by a user in a manual mode. The transmission system includes a user input device configured for manually changing the operational mode between the automatic and manual modes. The transmission system includes a transmission control unit for determining a recommended gear in the automatic and manual modes. In the manual mode, an operating gear of the transmission system is detected by the transmission control unit. A change of the operational mode from manual to automatic by means of the user input device is detected, and if the detected operating gear in the manual mode when changing to automatic mode is lower than the recommended gear, the sailing functionality in the automatic mode is deactivated.

A method is disclosed for operating a multi-gear vehicle transmission in a motor vehicle during a coasting phase. The coasting phase includes an overrun phase with a driving gear engaged and a freewheeling phase with the neutral gear engaged. It is determined whether the motor vehicle is in the overrun phase of the coasting phase, whether a condition for a transition to the freewheeling phase of the coasting phase is fulfilled, and whether a transmission condition with elevated drag losses exists. If the motor vehicle is in the overrun phase of the coasting phase, if the condition for transition to the freewheeling phase is fulfilled, and if a transmission condition with elevated drag losses exists, then at least one further shifting element (D, E) is closed in addition to the shifting elements (A, B, C) of the driving gear, which are closed during the overrun phase of the motor vehicle.

A method for operating a vehicle drivetrain (1) includes proceeding, in the presence of the demand for activation of the engine start-stop function of the vehicle drivetrain (1) and a simultaneously shut-down drive machine (2), from an operating state of the vehicle drivetrain (1) during which a sailing operating function of the vehicle drivetrain (1) is active, during which the drive machine (2) is decoupled from the drive output (3), during which the positively engaging shift element (F) is open and during which a rotational speed (n_ab) of the drive output (3) is higher than a defined rotational speed at which a rotational speed difference between shift element halves of the positively engaging shift element (F) lies within a rotational speed range within which the positively engaging shift element (F) is transferrable into the closed operating state, and actuating the positively engaging shift element (F) in a closing direction no later than when the defined rotational speed is reached.

A running control device has an engine coupling running mode enabling an engine brake running mode performed by coupling an engine and wheels with an engine brake applied by driven rotation of the engine, and an inertia running mode performed with an engine brake force lower than that of the engine brake running mode. The running control device includes a steering wheel steering angle as a condition of terminating the inertia running mode. The running control device performs a first inertia running mode with the rotation of the engine stopped and a second inertia running mode with the engine rotating. The first inertia running mode is terminated when the steering angle becomes equal to or greater than a predefined first determination value. The second inertia running mode is terminated when the steering angle becomes equal to or greater than a predefined second determination value larger than the first determination value.

A controller includes a control unit which is configured to execute a coast stop control. The coast stop control is configured to perform automatic stopping of the drive source while the vehicle is traveling, when a permitting condition is satisfied, the permitting condition including a condition that a speed ratio R of the variator is lower than a first threshold R1 while the lock-up clutch is in an engaged phase. The control unit is configured to prohibit execution of the coast stop control in a case in which an input-output rotation speed difference of the torque converter is equal to or more than a predetermined value when the lock-up clutch is in the engaged phase.

Provided is a vehicle control device with which improved fuel economy and lowered exhaust gas emissions can be effectively achieved without adversely affecting the driver when traveling while following a leading vehicle. The present invention has: a following-determination means that, during travel while following a leading vehicle, determines, on the basis of the speed of the host vehicle, the speed of the leading vehicle, and the distance from the leading vehicle, whether the host vehicle will be able to follow the leading vehicle by coasting; and an idle stop determination means that, when the following-determination means has determined that the host vehicle will be able to follow the leading vehicle by coasting, and the driving/travel state of the host vehicle satisfies other traveling idle stop criteria, determines that a traveling idle stop should be performed; and is provided with a determination criteria updating means for updating the determination criteria for the idle stop determination means in regard to criteria such as the leading vehicle characteristics, road surface conditions, and weather. In the event that it has been determined, from the determination conditions that have been updated in regard to the leading vehicle characteristics, etc., that following by coasting is possible, a control to shut off the on-board engine is performed.

An electronic control unit permits a shift operation to a neutral position, by which a manual transmission 14 is switched to neutral, during coasting control. Accordingly, shifting to the neutral position can be performed only by the shift operation. Thus, power transmission can be blocked after termination of the coasting control. In addition, the electronic control unit prohibits the shift operation to a particular gear after the transmission is switched to neutral. Thus, overreving or underreving at the termination of the coasting control can be suppressed.

A method is disclosed for operating a multi-gear vehicle transmission in a motor vehicle during a coasting phase. The coasting phase includes an overrun phase with a driving gear engaged and a freewheeling phase with the neutral gear engaged. It is determined whether the motor vehicle is in the overrun phase of the coasting phase, whether a condition for a transition to the freewheeling phase of the coasting phase is fulfilled, and whether a transmission condition with elevated drag losses exists. If the motor vehicle is in the overrun phase of the coasting phase, if the condition for transition to the freewheeling phase is fulfilled, and if a transmission condition with elevated drag losses exists, then at least one further shifting element (D, E) is closed in addition to the shifting elements (A, B, C) of the driving gear, which are closed during the overrun phase of the motor vehicle.

A controller includes a control unit which is configured to execute a coast stop control. The coast stop control is configured to perform automatic stopping of the drive source while the vehicle is traveling, when a permitting condition is satisfied, the permitting condition including a condition that a speed ratio R of the variator is lower than a first threshold R1 while the lock-up clutch is in an engaged phase. The control unit is configured to prohibit execution of the coast stop control in a case in which an input-output rotation speed difference of the torque converter is equal to or more than a predetermined value when the lock-up clutch is in the engaged phase.