An electronic transmission range select actuator (ETRSA) includes a primary drive system that operates during normal operation. The ETRSA includes an output shaft that is connected to the system via a lock pin during normal operation. The ETRSA also includes a release mechanism having a secondary motor that operates during a power loss or failure of the system. The secondary motor drives a gear that rotates freely relative to the output shaft. Rotation of the gear results in axial movement of the gear toward the lock pin, which in turn causes disengagement of the lock pin from the output shaft, allowing the output shaft to rotate due to the biasing load of a torsion spring such that the output shaft is returned to the P-range position. Thus, the mechanism is configured to return the output shaft to the P-range during a power loss or failure of the first motor.

An actuation unit has a primary motor and a transmission mechanism for transmitting motion generated by the primary motor to a control member. The transmission mechanism includes a first transmission member connected to a drive shaft of the primary motor, a second transmission member drivingly connected to the control member, and a coupling member shiftable between an engagement position and a disengagement position. The transmission mechanism further includes a first elastic member interposed between the first transmission member and the second transmission member to cause rotation of the second transmission member relative to the first transmission member when the coupling member is in the disengagement position, a second elastic member for elastically urging the coupling member towards the engagement position, and an auxiliary actuation device for shifting the coupling member from the engagement position to the disengagement position.

A failure judgment device of an automatic transmission includes: a first abnormality judging section configured to judge a power supply fault abnormality or a breaking abnormality of the solenoid, from a selected shift stage and a state of the transmission mechanism, after the detection of the electric abnormality; and a second abnormality judging section configured to judge the power supply abnormality or the breaking abnormality of the solenoid, from the monitor current value when the solenoid valve is switched to an OFF state, after the detection of the electric abnormality, when one of the first abnormality judging section and the second abnormality judging section judges the power supply fault abnormality or the breaking abnormality, the judgement result being outputted.

An electronic transmission range select actuator (ETRSA) includes two independent drive systems that are each able to actuate a common shaft, for example an output shaft of the ETRSA, via a coupling device disposed between and connecting the gear trains of each system. The first drive system of the two independent drive systems is used during normal vehicle operation to change the transmission gear range to a desired gear range. The second drive system is used in case of abnormal operation of the first drive system to return the vehicle transmission to the park transmission range.

Provided are a variator and a transmission controller in an engine-driven vehicle. The transmission controller has an instantaneous interruption recovery control portion configured to, upon a power reset from an instantaneous interruption during running, set a target through transmission ratio and a desired through transmission ratio to a lowest transmission ratio value by initialization and perform recovery control to recover an actual through transmission ratio of the variator to a transmission ratio value for shifting to normal control. The instantaneous interruption recovery control portion is further configured to, upon the power reset from the instantaneous interruption during the running, set a change speed of the target through transmission ratio from the lowest transmission ratio value to the desired through transmission ratio, to be higher than that under the normal control, before a time at which the desired through transmission ratio value deviates from the lowest transmission ratio value.

A backup power supply system of the present invention includes a first auxiliary power supply and a second auxiliary power supply capable of supplying electric power to a first load when failure of a main power supply occurs. In the backup power supply system, a second duration is shorter than a first duration. The first duration is the duration until the first auxiliary power supply becomes capable of supplying electric power to the first load. The second duration is the duration until the second auxiliary power supply becomes capable of supplying electric power to the first load.

A range switching apparatus of a shift-by-wire system has: a main motor; a deceleration mechanism that amplifies torque generated by the main motor; an output shaft that outputs the torque amplified by the deceleration mechanism; an auxiliary motor; and an emergency drive mechanism. The emergency drive mechanism is disposed on the auxiliary motor shaft of the auxiliary motor, and that is connected to or disconnected from the deceleration mechanism by driving of the auxiliary motor. The emergency drive mechanism transfers output of the auxiliary motor to the deceleration mechanism, and rotates the output shaft by being connected to the deceleration mechanism.

A method for operating a pneumatic actuating system of a transmission. The actuating system has an air reservoir at a first pressure. The reservoir couples an actuating space of the actuating system which is at a second pressure, and the actuating space couples, via control valves, shifting cylinders. When conducting a transmission gearshift, an air mass delivered to the active shifting cylinders via corresponding control valves, and an air mass sum including a nominal air mass in the active cylinders required for accomplishing the gearshift and an actual basic leakage from the activated shifting cylinder are determined. A defect leak in the pneumatic actuating system is recognized, if the air mass delivered to the active shifting cylinders is larger than the air mass sum. If a defect leak is recognized, the control valves coupling the actuating space and the shifting cylinders are shut off for a period of time.

A position detection device includes two detection systems that are respectively fed from power supply systems different from each other, and displace together with a shift lever. Each detection system can output detection patterns with four digits. A detection pattern when being located at a given position is different from a detection pattern when being located at another position. In any detection pattern, outputs of certain two digits among the four digits are set so as to be identical to each other, and to be different from outputs of two other digits. Alternatively, outputs of certain three digits among the four digits are set to be identical to each other, and to be different from an output of another digit.

An actuator to set a park lock of an automatic transmission of a motor vehicle has a drive (2) driving a drive shaft (1), a first actuating element (3) operatively connected to the drive shaft (1) for actuating a switching device, a spring element (5), which is supported on one side on a housing component (16) of the actuator, and on the other side on a second actuating element (17) designed to load the spring element (5). The actuator also has an electromagnetic retaining device (32) with an electromagnet (50) which interacts magnetically with a magnetic armature (52) comprising a ferromagnetic material component to retain the spring element (5) which is under loading, building up a spring return force. The magnetic armature (52) is mounted tiltably and/or pivotably on a pivot component (55) of the retaining device (32).