Abstract: 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.

Abstract: 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.

Abstract: In an automatic transmission of a motor vehicle, in which a hydraulic pressure is supplied to a piston of a friction element is maintained at a first level that is lower than a given level at which the friction element is engaged, while the vehicle that is in a forward-drive range is being stopped, when the range of the automatic transmission is changed from a neutral range to the forward-drive range the hydraulic pressure having a second level that is higher than the first level is supplied to the piston of the friction element until a completion of the stroke of the piston is detected. The stroke completion of the piston is judged based on a predetermined difference between a turbine speed of the automatic transmission detected upon the change of the range and a current turbine speed.

Abstract: Disclosed herein is a speed change transition control apparatus for an automatic transmission. The speed change transition control apparatus comprises rotational speed detection unit for detecting an input shaft rotation speed of the speed change mechanism, and a feedback control unit for controlling engagement pressure through a fluid pressure control element in such a manner that the input shaft rotation speed during a speed change follows a target rotation slope with an actual input shaft rotation speed detected at an actual inertia phase start point by the rotational speed detection unit as its starting point.

Abstract: Under a condition where a manual mode is selected by a selecting lever, when a down-shift switch is turned ON and down-shift is requested, an engine speed NED after the down shift is calculated (step S12), and if this engine speed exceeds the overspeed NOV, the down-shift is made to stand by, and a down-shift elapsed time T1 is incremented. When the incremented elapsed time is within a down-shift effective time TD (predetermined time) which is set on the basis of a gear position, throttle opening degree, vehicle speed, deceleration, etc., a down-shift command is sent (step S18) when the engine speed NED reaches the overspeed NOV or lower, whereas when the down-shift elapsed time T1 reaches the down-shift effective time TD or longer, the down-shift stand-by condition is released (step S17).

Abstract: A control device for a motor vehicle includes a central processing unit that is coupled to a non-volatile memory, a volatile memory and a key switch. The control device ensures transmission of data between memories with high reliability when control operation is repeatedly stopped and started upon the turn-off and turn-on of the key switch, while assuring a reduced period of time during which power is supplied from a back-up power supply to the device, and with a reduced frequency of writing of the data.

Abstract: A neutral control device of an automatic transmission of a motor vehicle is provided in which a neutral control condition is satisfied when an accelerator pedal is released while a forward drive range is being selected, and a hydraulic oil pressure applied to a forward drive engaging element that is to be engaged in the forward drive range is controlled using a line pressure as an original pressure, so that the forward drive engaging element has no engaging capacity when the neutral control condition is satisfied.

Abstract: A method and system for controlling shift in an automatic transmission that can establish a plurality of gear ratios by selectively supplying a hydraulic pressure for a plurality of frictional engaging elements.

Abstract: When a speed ratio is selected manually by an operator of a vehicle, an upshift command is generated if the engine speed exceeds a predetermined maximum value. Further manual upshifts and downshifts are inhibited for a predetermined time period. The time period is a function of at least one of the current engaged gear ratio, engine throttle position, and the amount of time it takes to upshift the transmission.

Abstract: An auxiliary brake apparatus is provided that includes an exhaust brake system for restricting a channel area of an exhaust passage so as to increase a resistance to rotary motion of an engine, and a retarder disposed between an automatic transmission and vehicle wheels, for generating a braking force that resists an engine brake torque transmitted to the automatic transmission.

Abstract: An automatic transmission learning control apparatus comprises a memory for storing parameters in memory locations specified for respective gear shift operation modes. A physical quantity related to a gear shift operation made in the automatic transmission is measured. The parameter stored in the memory location specified by the sensed gear shift operation mode is updated in a direction to bring the physical quantity into agreement with a target value. The parameter to be updated is limited between upper and lower limits set for each of the gear shift operation modes. The parameter stored in the memory location specified by the sensed gear shift operation mode is used to control the gear shift operation.

Abstract: A working fluid pressure control system for an automatic power transmission includes a pre-charge pressure regulating mechanism for temporarily elevating a working fluid pressure abruptly and subsequently drop the working fluid pressure for generating a pre-charging constant pressure for a start-up friction element, and a detecting portion for detecting an operational range before selection of neutral range. When selection is made from neutral range to a traveling range, and the traveling range is different from the operational range before selection of the neutral range, the pre-charge pressure regulating mechanism is actuated when judgement is made that the start-up friction element engaged in the operational range before selection of neutral range is released, thus selection being performed within a short period without accompanying with a shock.

Abstract: In response to a signal indicating the present throttle valve opening degree detected by a throttle valve sensor and a signal indicating the present vehicle speed detected by a vehicle speed sensor, a lock-up controller determines whether a lock-up clutch should be brought into the operatively connected state or it should be released from the operatively connected state, and on completion of the foregoing determination, the controller outputs a certain signal to a solenoid valve. In the case that the lock-up clutch has been released, this state is maintained. On the contrary, in the case that the lock-up clutch has been in the operatively connected state, the controller determines whether maintains this state or selects a lock-up clutch releasing pattern depending on the present throttle valve opening degree.

Abstract: In response to a signal indicating the present throttle valve opening degree detected by a throttle valve sensor and a signal indicating the present vehicle speed detected by a vehicle speed sensor, a lock-up controller determines whether a lock-up clutch should be brought into the operatively connected state or it should be released from the operatively connected state, and on completion of the foregoing determination, the controller outputs a certain signal to a solenoid valve. In the case that the lock-up clutch has been released, this state is maintained. On the contrary, in the case that the lock-up clutch has been in the operatively connected state, the controller determines whether maintains this state or selects a lock-up clutch releasing pattern depending on the present throttle valve opening degree.

Abstract: When on-going down-shifting state of an automatic transmission is detected, an output torque of an engine is lowered after expiration of a first predetermined period, which is set between detection of down-shifting and a timing immediately before completion of down shifting, and for a second predetermined period which is set for a given period to completion of down-shifting from expiration of the first predetermined period to suppress a shift shock.

Abstract: A gear control means determines the gear position of an automatic transmission based on a vehicle speed V and throttle opening T input from a vehicle speed sensor and throttle opening sensor, and on a predetermined gear change-over lines which take form of kinked lines expressing "vehicle speed/throttle opening" characteristics for up-shifting and down-shifting respectively. The gear control means is provided with a memory unit and a gear determining unit.

Abstract: An automotive automatic transmission includes a one-way clutch and solenoids which, when switched in ON-OFF manner, induces a speed change of the transmission. The rotation speed ratio between input and output shafts of the transmission is obtained. When a speed change becomes necessary, a judgment is carried out as to whether the necessary speed change is of a type which needs the engaged condition of the one-way clutch or not. If the speed change needs the engaged condition of the one-way clutch, switching of the solenoids is carried out when the rotation speed ratio comes to a predetermined value, while, if the speed change does not need the engaged condition of the one-way clutch, switching of the solenoids is carried out when a predetermined time is passed from the time when the necessity of the speed change is made.

Abstract: An air conditioner control device is applied to an air conditioner of an automotive vehicle equipped with an automatic transmission. The air conditioner control device controls the on-off switching operation of a compressor of the air conditioner. The control device turns off the operation of the compressor when a signal indicative of accelerating state of an automotive vehicle from a transmission controller is received. Further, the control device restarts the operation of the compressor when the off-time of the compressor becomes larger than a first predetermined time and when a second predetermined time has elapsed form a shifting judgment in the automatic transmission. Therefore, the operation of the air conditioner is stopped during an acceleration of the automotive vehicle and securely restarred after the acceleration.

Abstract: An operation mode control system for an automatic automotive power transmission includes a manually operable mode selection switch for selecting an operation mode from among economy, power, and hold modes. When an acceleration demand magnitude is larger than a criterion value while the hold mode is selected, the execution of the hold mode is suspended. This suspension of the hold mode execution is automatically released without operating the manually operable mode selection switch when certain conditions are reached. The power mode may be executed in place of the hold mode during the suspension of the hold mode execution.

Abstract: According to a select shock attenuating method, line pressure, under which hydraulic fluid is supplied to hydraulically actuable and frictionally engageable coupling or couplings which are assigned to establish a gear ratio in an automatic transmission, is controlled. The automatic transmission has a plurality of selectable modes. In one mode, an appropriate one gear ratio state for a motor vehicle to start under normal road condition is established after placing a manual valve to a drive range position from a non-drive range position, while in another mode the automatic transmission is conditioned to another gear ratio.