A method for managing emissions from a vehicle having an aftertreatment system is provided. The method includes: receiving, by a controller, information indicative of a temperature of an aftertreatment system of the vehicle and a power output of an engine of the vehicle; comparing, by the controller, the temperature of the aftertreatment system to a temperature threshold; comparing, by the controller, the power output to a power output threshold; and responsive to the comparisons, commanding, by the controller, an aftertreatment system heater to selectively engage and disengage to warm the aftertreatment system of the vehicle.

Methods and systems are provided for controlling engine operation in response to a request to shift a transmission gear. In one example, a method may include maintaining operating conditions of an engine and redirecting electric power generated via the engine from a traction motor to a battery in response to a request to shift a transmission while the driveline is operating in a series mode. In this way engine efficiency may be improved and a time frame for shifting a transmission gear may be reduced responsive to a gear shift request while the powertrain is operating in series mode.

A hybrid sub-assembly for driving a vehicle includes at least one primary shaft, at least one secondary shaft, a transmission gearbox including at least one intermediate shaft different from the primary shaft and the secondary shaft, and an electromotive unit. The electromotive unit includes at least one reversible electric machine, and a coupling device that can take up at least one intermediate coupling position in which an output shaft of the reversible electric machine is kinematically connected to the intermediate shaft, and a secondary coupling position in which an output shaft of the reversible electric machine is kinematically connected to the secondary shaft without going via the intermediate shaft.

The object of the invention is to travel backward by an engine alone in a state where an electric motor is disconnected. Thus, external teeth are formed on the outer periphery of a ring gear which meshes with a first sun gear via a first pinion gear and a second pinion gear and to which power input from an electric motor is transmitted; a power transmission mechanism further includes a gear meshing with the external teeth of the ring gear; and a second clutch capable of non-rotatably fixing the ring gear at the time of causing a vehicle to travel backward with power input from an engine is provided between the ring gear and a transmission case.

The object of the invention is to travel backward by an engine alone in a state where an electric motor is disconnected. Thus, external teeth are formed on the outer periphery of a ring gear which meshes with a first sun gear via a first pinion gear and a second pinion gear and to which power input from an electric motor is transmitted; a power transmission mechanism further includes a gear meshing with the external teeth of the ring gear; and a second clutch capable of non-rotatably fixing the ring gear at the time of causing a vehicle to travel backward with power input from an engine is provided between the ring gear and a transmission case.

A system and method for controlling a hybrid vehicle having an engine, a traction motor, and an automatic step-ratio transmission having a plurality of selectable discrete gear ratios, a torque converter, and sharing a common cooling fluid or oil with the traction motor, include a controller configured to shift the automatic step-ratio transmission to neutral in response to vehicle speed being below a threshold with the engine idling while temperatures of at least two of: the traction battery, the electric machine, and the transmission are above associated thresholds to reduce heat generation by the torque converter due to oil shear with the torque converter stalled. The controller may shift the transmission to drive in response to release of a brake pedal. A neutral shift may also be performed in response to high-voltage accessory loads or on-board generator loads exceeding a threshold.

A system and method for controlling a hybrid vehicle having an engine, a traction motor, and an automatic step-ratio transmission having a plurality of selectable discrete gear ratios, a torque converter, and sharing a common cooling fluid or oil with the traction motor, include a controller configured to shift the automatic step-ratio transmission to neutral in response to vehicle speed being below a threshold with the engine idling while temperatures of at least two of: the traction battery, the electric machine, and the transmission are above associated thresholds to reduce heat generation by the torque converter due to oil shear with the torque converter stalled. The controller may shift the transmission to drive in response to release of a brake pedal. A neutral shift may also be performed in response to high-voltage accessory loads or on-board generator loads exceeding a threshold.

A method for performing rotational speed synchronisation of a first transmission component having a first initial rotational speed with a second transmission component having a second initial rotational speed, so that they rotate with the same final rotational speed during a gear switch from an initial driving gear to a final driving gear in a stepped gear transmission for a hybrid electric or electric drive train having an electric traction motor. The method including calculating a total frictional work resulting from performing the total rotational speed synchronisation by means of a mechanical synchroniser of the stepped gear transmission only, and if the calculated total frictional work exceeds a maximal frictional work of the mechanical synchroniser, performing the rotational speed synchronisation by means of both the electric traction motor and the mechanical synchroniser.

A method for performing rotational speed synchronisation of a first transmission component having a first initial rotational speed with a second transmission component having a second initial rotational speed, so that they rotate with the same final rotational speed during a gear switch from an initial driving gear to a final driving gear in a stepped gear transmission for a hybrid electric or electric drive train having an electric traction motor. The method including calculating a total frictional work resulting from performing the total rotational speed synchronisation by means of a mechanical synchroniser of the stepped gear transmission only, and if the calculated total frictional work exceeds a maximal frictional work of the mechanical synchroniser, performing the rotational speed synchronisation by means of both the electric traction motor and the mechanical synchroniser.

Methods and systems are provided for controlling and diagnosing a mechanical vehicle component. In one example, a method may include determining an input device state and an electric machine torque at a diagnostic controller, and identifying a fault condition based on these determinations. Further, the diagnostic controller may trigger an active fault state of the mechanical vehicle component to avoid unintended vehicle acceleration, particularly at low speeds.