Abstract: If oil temperature is equal to or higher than a predetermined temperature and if accelerator opening change rate is equal to or higher than a predetermined change rate upon detection of a downshift instruction, an ECT-ECU sets modes corresponding to conditions for determination period calculation processings, hydraulic-pressure temporal change rate calculation processings, and torque adjustment amount calculation processings, respectively. By performing downshift on the basis of a determination period, a hydraulic-pressure temporal change rate, and a torque adjustment amount corresponding to a set mode, the ECT-ECU improves gear-shift responsive characteristics and restrains the occurrence of a gear-shift shock.

Abstract: An ECT-ECU includes an abrupt turbine speed increase learning control circuit which prevents simultaneous release of both a frictional engagement element to be released and a frictional engagement element to be engaged, a tie-up learning control circuit which prevents simultaneous engagement of both the frictional engagement element to be released and the frictional engagement element to be engaged, a determination circuit that determines whether one of tie-up learning control and abrupt turbine speed increase learning control is necessary based on the turbine speed, and a control circuit that prohibits execution of the tie-up learning control unless the number of trips after the abrupt turbine speed increase learning control has been executed is at least equal to a predetermined number, when it has been determined that the tie-up learning control is necessary.

Abstract: A vehicular automatic shift control unit for executing a cooperative shift control (an upshift inhibition and a downshift) of an automatic transmission based on an information associated with a road condition around a vehicle or a road condition in front of the vehicle, is provided with judging means for judging whether a vehicle exists in a predetermined area including a branch point of the road during execution of the cooperative shift control, and gear ratio maintaining control means for maintaining a gear ratio of the automatic transmission if it is judged that the vehicle exists in the predetermined area.

Abstract: An automatic transmission control device controls multiple speed changes in which shifting from first speed to second speed occurs during shifting from second speed to first speed. The control device includes a shift lever position sensor, an ECT_ECU, and an AT linear solenoid. The ECT_ECU includes a circuit that detects multiple speed changes; a circuit that controls the AT linear solenoid such that an engagement pressure of an engaged first speed engine brake friction element sweeps down when multiple speed changes are detected; and a circuit that commands a shift to second speed once a predetermined time has passed since the detection of multiple speed changes assuming that the engagement pressure of the first speed engine brake friction element has sufficiently swept down.

Abstract: When a shift routine is not being executed in an automatic transmission and a difference between an actual turbine speed and a calculated synchronous speed is equal to, or greater than, a preset value &agr;, a difference &Dgr;NT between an estimated turbine speed and the actual speed when the automatic transmission is in a neutral state is calculated. When &Dgr;NT is equal to, or less than, a preset value &bgr;, it is determined that a failure related to the neutral state of the automatic transmission has occurred. Also, when &Dgr;NT is greater than a preset value &bgr;, it is determined that a failure related to slipping of a frictional engaging element has occurred.

Abstract: If oil temperature is equal to or higher than a predetermined temperature and if accelerator opening change rate is equal to or higher than a predetermined change rate upon detection of a downshift instruction, an ECT-ECU sets modes corresponding to conditions for determination period calculation processings, hydraulic-pressure temporal change rate calculation processings, and torque adjustment amount calculation processings, respectively. By performing downshift on the basis of a determination period, a hydraulic-pressure temporal change rate, and a torque adjustment amount corresponding to a set mode, the ECT-ECU improves gear-shift responsive characteristics and restrains the occurrence of a gear-shift shock.

Abstract: An automatic transmission control device controls multiple speed changes in which shifting from first speed to second speed occurs during shifting from second speed to first speed. The control device includes a shift lever position sensor, an ECT_ECU, and an AT linear solenoid. The ECT_ECU includes a circuit that detects multiple speed changes; a circuit that controls the AT linear solenoid such that an engagement pressure of an engaged first speed engine brake friction element sweeps down when multiple speed changes are detected; and a circuit that commands a shift to second speed once a predetermined time has passed since the detection of multiple speed changes assuming that the engagement pressure of the first speed engine brake friction element has sufficiently swept down.

Abstract: An ECT-ECU includes an abrupt turbine speed increase learning control circuit to avoid a situation in which both a frictional engagement element to be released and a frictional engagement element to be engaged are in a state of release at the same time, a tie-up learning control circuit to avoid a situation in which both the frictional engagement element to be released and the frictional engagement element to be engaged are in a state of engagement at the same time, a determination circuit that determines whether one of tie-up learning control and abrupt turbine speed increase learning control is necessary based on a signal input from a turbine speed sensor, and a control circuit that prohibits execution of the tie-up learning control unless the number of trips after the abrupt turbine speed increase learning control has been executed is equal to, or greater than, a predetermined number, when it has been determined that the tie-up learning control is necessary.

Abstract: In the case where a cooperative gear change control of an automatic transmission is executed on the basis of information with respect to a condition around a vehicle or in front of a vehicle, in a cooperative gear change control means, a gear change of the automatic transmission is directly determined on the basis of actual curve information and road surface inclination information in accordance with a previously stored downshift map, and a gear stage is switched such that a determined gear change is executed. Therefore, it is possible to directly obtain the gear stage or the gear ratio corresponding to the curve of the road and the inclination of the road surface.

Abstract: In the case where a cooperative gear change control of an automatic transmission is executed on the basis of information with respect to a condition around a vehicle or in front of a vehicle, in a cooperative gear change control means, a gear change of the automatic transmission is directly determined on the basis of actual curve information and road surface inclination information in accordance with a previously stored downshift map, and a gear stage is switched such that a determined gear change is executed. Therefore, it is possible to directly obtain the gear stage or the gear ratio corresponding to the curve of the road and the inclination of the road surface.

Abstract: A vehicular automatic shift control unit for executing a cooperative shift control (an upshift inhibition and a downshift) of an automatic transmission based on an information associated with a road condition around a vehicle or a road condition in front of the vehicle, is provided with judging means for judging whether a vehicle exists in a predetermined area including a branch point of the road during execution of the cooperative shift control, and gear ratio maintaining control means for maintaining a gear ratio of the automatic transmission if it is judged that the vehicle exists in the predetermined area.

Abstract: The present invention offers a control device for an automatic transmission mounted on a vehicle which prevents a shock caused by sudden working of a one-way clutch, when the vehicle accelerates after a deceleration near an intersection or in an intersection. The control device includes an automatic transmission having at least a one-way clutch and achieving a down-shift by applying the one-way clutch, a driving environment detector, a low speed condition detector, and a prohibition means. The driving environment detector detects a driving environment of a vehicle including the automatic transmission. The low speed condition detector detects when the vehicle approaches or enters into a place indicative of a down-shift of the automatic transmission, and the prohibition means prohibits a down-shift caused by applying the one-way clutch when the low speed condition detector detects that the down-shift is indicated.