Abstract: The fail-safe gear step switching valve (120) can be switched to the first position to establish the low-speed side fail-safe gear step (third speed-change gear step) or the second position to establish the high-speed side fail-safe gear step (fifth speed-change gear step). Upon the failure state of the solenoid valve device (SLC1, SLC2), the fail-safe gear step switching valve is held at the second position by the line hydraulic pressure (PL1). Two kinds of the fail-safe gear steps i.e., the third speed-change gear step and the fifth speed-change gear step can be established depending on the vehicle state just before the failure occurrence of the fail-safe gear step switching valve. Even if the D?N operation of the shift lever (72) is performed during the vehicle running in the fifth speed-change gear step, the fail-safe gear step switching valve remains at the second position to establish the fifth speed-change gear step even upon the shifting operation of the shift lever to the “D” position again.

Abstract: A method of regulating operation of an automatic transmission includes identifying a tie-up condition of the automatic transmission, adjusting a pressure of a transmission element in response to the tie-up condition and determining whether a first gear ratio of the automatic transmission holds. The pressure is set to zero if the gear ratio does not hold and a faulty transmission element is identified as one associated with a second gear ratio that is lower than said first gear ratio.

Abstract: A fault-tolerant gear selector lever position apparatus is described. Included is a first sensor operable to detect each position, and a second sensor operable to detect subsets of the positions. A first controller monitors the second sensor, and a second controller monitors the first sensor. The second controller identifies and communicates one of the positions to the first controller, and the first controller validates the position and communicates the position to a control system. The lever is applicable to a power transmission device. Each sensor preferably comprises digital encoding sensor; the first sensor generates a unique signal for each position, and the second sensor generates a unique signal for each subset of the positions, preferably a unique signal for each of Park, Reverse, Neutral, and Forward Drive. The controllers identify faults in the sensors, and communicate and act accordingly.

Abstract: In a shift control device and a shift control method of an automatic transmission that establishes a plurality of gear steps of different speed change ratios by selectively engaging a plurality of friction engagement devices, one of a shift start time point and an inertia phase start time point is used as a reference time. In a power-off shift, the shift action is compulsorily ended when the elapsed time from the reference time exceeds a first time. In a power-on shift, the shift action is compulsorily ended when the elapsed time from the reference time exceeds a second time that is set shorter than the first time. If a switch from the power-off shift to the power-on shift occurs halfway through the power-off shift, the shift action is compulsorily ended when the elapsed time from the time point of the switch exceeds a predetermined time.

Abstract: A power output apparatus that suppresses wearing-out of the components of a transmission connected to a drive shaft and a rotating shaft of an electric motor as well as reducing the a shock imparted to the vehicle. The required drive power is output to the drive shaft by appropriately controlling and internal combustion engine, a power split device, the electric motor and a shifting portion. When the rotational speed of the drive shaft can be estimated, the speed ratio in the shifting portion is changed based on either the detected rotational speed of the drive shaft or the estimated rotational speed of the drive shaft and the rotational speed of the rotating shaft. However, when the rotational speed of the drive shaft cannot be estimated, the speed ratio is maintained in the shifting portion.

Abstract: There is provided a fail control apparatus for an automatic transmission, which, in the event of a friction element failure, is capable of coping with the failure by identifying a failed part without erroneous determination and within a short time. The set gear ratio of a designated gear position at the time of failure and the actual gear ratio are compared with each other to determine whether a friction element has failed, and an alternative gear position which enables a vehicle to start moving again is designated based on the determination result. In determining a failed friction element, one friction element disengaged or engaged due to failure is identified only when the designated gear position is the first speed gear position which is achieved by engaging one low clutch and a one-way clutch. It is therefore possible to determine the details of failure with accuracy and properly set an alternative gear position.

Abstract: An automatic transmission includes a planetary gear arrangement, and a plurality of engaging elements each arranged to vary an engagement state among the rotating elements of the planetary gear arrangement in such a manner to establish a normal gear ratio set and an emergency gear ratio set excluded from the normal gear ratio set. A control section of the automatic transmission performs the following: selecting a gear from the normal gear ratio set in accordance with a running state of a vehicle under normal operating conditions; controlling the engagement state of each of the engaging elements in such a manner to shift into the selected gear; detecting a failure in the engaging elements; selecting an escape gear ratio set from the normal gear ratio set and the emergency gear ratio set; and driving the vehicle with the escape gear ratio set when a failure is detected in the engaging elements.

Abstract: A fail detecting apparatus for an automatic transmission which is capable of quickly detecting a failure of an oil pressure switch with accuracy. In addition to an oil pressure switch state determining process carried out while a vehicle is running, the state of an oil pressure switch is detected at the time of turning-on of an ignition switch before an engine is started, and if the oil pressure switch has continued to be ON until a timer value becomes equal to or greater than a predetermined value, it is determined that the oil pressure switch has failed. Since the state of the oil pressure switch is determined before the engine is started, i.e. in the state in which no oil pressure has been generated, whether the oil pressure switch is normal or has failed can be determined with high accuracy irrespective of which range is currently selected in the automatic transmission.

Abstract: To improve the safety of automated gearboxes, it is proposed that terminal positions of internal gearshift members and external actuation members be so defined separately from each other that one can recognize whether the engagement of a speed is accompanied by the attainment of a terminal position of an internal gearshift member or an external actuation member. Error analysis is possible in this way. For dual clutch gears, it is additionally proposed that one can, at least in gearshift operations that are critical in terms of safety, disengage on speed of a subgear in a separate procedure, before a new speed of this subgear can be engaged.

Abstract: At the time of a failure in the second group of engagement devices, the manner of input of oil pressures to a fail-safe valve group is changed via a priority degree switching valve on the basis of the state of engagement of engagement devices of the first group in such a manner that the predetermined degrees of priority for the supply of one of oil pressures PC4, PB1 output from linear solenoid valves SL4, SL5 to a corresponding one of a clutch C4 and a brake B1 via the fail-safe valve group are changed so as to avoid an event that the fail-safe gear stage established in order to prevent the occurrence of interlock of the automatic transmission involves a downshift of two or more stages from the speed change stage maintained immediately prior to the occurrence of the failure. Therefore, it is possible to prevent the occurrence of an uncomfortable behavior of the vehicle caused by the shift to the fail-safe gear stage.

Abstract: A method and an apparatus are provided to control operation of an electro-mechanical transmission device selectively operative in one of a plurality of fixed gear modes and two continuously variable modes. The method comprises controlling the flow control devices of the electro-hydraulic control circuit, and monitoring a plurality of pressure monitoring devices in the electro-hydraulic control circuit. A fault is identified in the electro-hydraulic control circuit when a signal output of one of the pressure monitoring devices does not correspond to an expected signal output for the pressure monitoring device after an elapsed time period.

Abstract: In an automatic transmission control system and method, an electronic control unit is programmed to output a command to establish another gear stage different from the gear stage at the time of occurrence of fault-induced disengagement by combination of engagements of the friction elements other than the friction elements to be engaged at the time of occurrence of fault-induced disengagement, and simultaneously output a plurality of commands to establish a plurality of gear stages corresponding to combination of engagements of the friction elements to be engaged and disengaged, respectively, at the gear stage at the time of occurrence of fault-induced disengagement, when the gear stage at the time of occurrence of the fault-induced disengagement is a predetermined gear stage and the friction element undergoing the fault-induced disengagement is not determined.

Abstract: A hydraulic control system of a seven-speed automatic transmission that provides enhanced overall performance by achieving precise and effective control by providing a fail-safe function in at least two ways.

Abstract: A method for controlling a hydraulic circuit for a twin-clutch transmission, wherein the hydraulic circuit comprises a first and a second clutch that can be hydraulically actuated, the pressures of said clutches being controlled with respective pressure control valves, and wherein a safety circuit substantially guarantees a safe state for the hydraulic circuit if a malfunction occurs. The safety circuit is configured such that if a partial malfunction affecting only one of the two clutches occurs, the affected clutch is disengaged and if a total malfunction affecting both clutches occurs, the clutch with the lower clutch pressure at the time of the total malfunction is disengaged and the other clutch with the higher clutch pressure at the time of the total malfunction remains engaged to maintain the transfer of torque via said clutch.

Abstract: The shift control apparatus for a continuously-variable transmission includes a primary pulley; a secondary pulley connected with the primary pulley by a belt; a shift actuator that varies a speed ratio; a line pressure adjusting that adjusts a line pressure; a secondary-pressure adjusting section that adjusts a secondary pressure; and a control section that controls the shift actuator, the line pressure adjusting section, and the secondary-pressure adjusting section. Moreover, the control section includes a fail determining section that determines whether the shift actuator is under a failed condition.

Abstract: A fault-tolerant gear selector lever position apparatus is described. Included is a first sensor operable to detect each position, and a second sensor operable to detect subsets of the positions. A first controller monitors the second sensor, and a second controller monitors the first sensor. The second controller identifies and communicates one of the positions to the first controller, and the first controller validates the position and communicates the position to a control system. The lever is applicable to a power transmission device. Each sensor preferably comprises digital encoding sensor; the first sensor generates a unique signal for each position, and the second sensor generates a unique signal for each subset of the positions, preferably a unique signal for each of Park, Reverse, Neutral, and Forward Drive. The controllers identify faults in the sensors, and communicate and act accordingly.

Abstract: A method of controlling at least a fifth characteristic operating value of a motor vehicle power train includes the step of performing an emergency adaptation of at least one of the stored clutch-disengagement thresholds during an operating phase of the motor vehicle, if predetermined third conditions are present. The method also includes the step of performing a nonemergency adaptation of at least one of the stored clutch-disengagement thresholds at the end of the operating phase if predetermined fourth conditions are present.

Abstract: Disclosed herein are systems and methods of controlling the pressure in a modulation pressure circuit through transmission fluid through an orificed check valve supplementary or in substitution of a computer-controlled pressure regulation solenoid. Detailed information on various example embodiments of the inventions are provided in the Detailed Description below, and the inventions are defined by the appended claims.

Abstract: A method of controlling a clutch-to-clutch transmission. The method includes detecting transmission slip speed that exceeds a predetermined amount for a predetermined time period. Based on the detecting, a shift of a gear ratio of the transmission is forced. When this method is implemented in a vehicle, loss of driver control of the vehicle can be prevented in the event of a non-commanded neutral condition in the transmission.

Abstract: An automotive automatic transmission control apparatus is provided which works to increase the power of an engine in response to a request to down-shift the gear of an automatic transmission for developing the engine braking. The control apparatus includes a fail-safe circuit working to stop increasing the power of the engine when a defect in operation of a transmission hydraulic control circuit is detected after the hydraulic control circuit starts to control the hydraulic pressures to achieve the downshift of the automatic transmission. This eliminates or alleviates a problem, such as unwanted acceleration of the vehicle during the control of the downshift in the transmission.

Abstract: An automatic transmission control apparatus controls a gear position by engaging and disengaging multiple frictional elements. A hydraulic pressure detector detects hydraulic pressure applied to the frictional elements. A failure determiner determines a failure, i.e., a dual-engagement of the frictional elements in accordance with detection signals of the hydraulic pressure detector. The hydraulic pressure detector detects first and second hydraulic pressure applied to the plurality of frictional elements. The second hydraulic pressure is greater than the first hydraulic pressure. The failure determiner determines a failure in accordance with a detection signals of the first and second hydraulic pressure detected by the hydraulic pressure detector.

Abstract: An engine (drive force) control apparatus for a motorcycle that prevents a change in vehicle behavior by noise or the like. A control CPU electronically controls injection and ignition of fuel and a throttle valve. An abnormality detecting portion detects an abnormality of the engine control apparatus by a predetermined abnormality detecting period. When the abnormality is detected, primary abnormality processing of the engine control apparatus is executed. When the abnormality is not detected, primary abnormality processing is released and an electronic control at normal time of the engine control apparatus is executed. When an abnormality detecting signal detected by the abnormality detecting portion continues even an elapse of a predetermined abnormality determining time period, primary abnormality processing is shifted to secondary abnormality processing.

Abstract: A device and method for fluid delivery in a continuously variable transmission that includes a valve assembly, configured to distribute a fluid, having a first position and a second position. A forward clutch, a reverse clutch, and a torque converter are connected to the valve assembly. The valve assembly in the first position regulates either the forward clutch or the reverse clutch and opens the torque converter. In the second position, the valve assembly closes the forward clutch or the reverse clutch and regulates the torque converter. A controller commands the valve assembly to the first position and detects if the valve assembly is stuck in the second position. The controller is able to detect the valve assembly stuck in the second position and attempt to unstuck it while the continuously variable transmission is in drive.

Abstract: A vehicle includes an engine that powers a wheel through a drive train. The drive train includes a continuously variable transmission (CVT) and toothed gearing disposed between the CVT and the wheel. A release clutch is also disposed between the CVT and the wheel. A controller controls the release clutch so as to disengage the clutch when the engine is not running and engage the clutch when the engine is running. The controller includes a hydraulic cylinder that fluidly connects to the engine's oil system so that engine-generated oil pressure engages the release clutch. Disengagement of the release clutch makes it easier to push the vehicle when the engine is not running, for example, when the engine breaks down.

Abstract: A controller for a transmission capable of preventing an occurrence of a gear squeak caused by a malfunction of a synchronization mechanism. The voltage determination section 24 performs a shift operation of a transmission by determining a control input Vin to a shift motor 13 so as to match an actual position Psc of a coupling sleeve 6 grasped by an actual position grasping section 21 with a target position Psc_cmd of the coupling sleeve 6 set by a target position setting section 22.

Abstract: The normal control of an electrically-activated hydraulic valve armature is overridden to automatically and periodically open the armature for flushing out debris that has accumulated between the armature and a seat that the armature is designed to engage. The valve develops fluid pressure for maintaining engagement of a motor vehicle transmission clutch, and when excessive slippage of the clutch is detected, the armature is forced into engagement with the seat until the slippage is reduced or a predetermined period of time has elapsed, after which the armature is temporarily positioned away from the seat to provide full flow of hydraulic fluid across the seat to flush out debris that prevents the armature from engaging the seat. During Neutral operation of the transmission, the armature is continuously positioned away from the seat, and during low torque conditions the armature is temporarily positioned away from the seat.

Abstract: A drive control apparatus able to hold an autonomously stabilized posture by a small size configuration by independently detecting abnormalities in a drive system of a first motor and a drive system of a second motor at controllers, outputting the results to majority decision circuits, and having the majority decision circuits turn switches on/off by majority decision based on the results.

Abstract: A transmission controller commands a demand torque of an engine to an engine controller according to an actual secondary pulley pressure that is detected by a secondary pulley pressure sensor when a vehicle speed is 0 km/h and a state wherein gear ratio is equal to or higher than a predetermined gear ratio is continued for a first predetermined time or more. Thereby, since an input torque corresponding to a secondary pulley pressure which is actually generated is inputted to a primary pulley even when a failure occurs in the secondary pulley rotation sensor, engine performance of a vehicle can be ensured.

Abstract: A control system for a vehicle includes an engine switch control unit for switching the operating condition of the engine between the all-cylinder operating condition and the partial-cylinder operating condition, a failure determining unit for determining the failure of the lockup clutch control device, and a coupling capacity change inhibiting unit for inhibiting a change in coupling capacity of the lockup clutch accompanied by the switch control of the operating condition of the engine by the engine switch control unit during the failure determination by the failure determining unit.

Abstract: A double clutch drive has a first and a second clutch, wherein for normal operation for the closing and opening of the first clutch a first hydraulic device governed by an electronic control is provided, and for the closing and opening of the second clutch a second hydraulic device is provided. Also, a position-holding hydraulic device is provided to which position signals are delivered corresponding to the momentary position of the first and second clutch, and which is connected via hydraulic control lines with the first and second hydraulic device, while in the event of a failure of the electronic control the position-holding hydraulic device hydraulically operates the first and the second hydraulic control such that, at least in many positions of the clutches, the clutch positions that are present immediately prior to the failure of the electronic control are sustained.

Abstract: In a gearbox control system (8) for detecting systematic errors and long-term changes, the behavior of a real gearbox (1) is compared to the behavior of an ideal gearbox (7), which is implemented in the form of a gearbox model in the gearbox control system (8).

Abstract: An apparatus is provided for controlling a joint force of a friction-joint component placed in a torque transmitting mechanism (e.g., transmission) mounted on a vehicle. The friction-joint component is connected to a drive source. The apparatus comprises a guideline producing unit, joint force controlling unit, and drive force controlling unit. The guideline producing unit produces a first target operation guideline for the torque transmitting mechanism and a second target operation guideline for the drive source. The first target operation guideline includes a transmitted torque capacity of the torque transmitting mechanism. The joint force controlling unit controls the joint force based on the first target operation guideline. The controlling unit includes a unit setting a value to the joint force depending on the information regulating the transmitted torque capacity. The drive force controlling unit controls a drive force of the drive source based on the second target operation guideline.

Abstract: A hydraulic control apparatus for switching an operation of a hydraulically operated mechanical apparatus, by selectively operating two frictional engagement elements of a first, a second, a third, and a fifth frictional engagement elements, the hydraulic control apparatus including a first control valve which, in association with an event that respective hydraulic pressures to operate the first and second frictional engagement elements are both produced, drains one of the third and fifth frictional engagement elements and outputs a control hydraulic pressure; and a second control valve which, when at least two hydraulic pressures of (a) the control hydraulic pressure and (b) respective hydraulic pressures to operate the third and fifth frictional engagement elements are supplied to the second control valve, drains the other of the third and fifth frictional engagement elements.

Abstract: A control device for electric motors and a method for monitoring the serviceability of a transmission part arranged for transmission of torque between an electric motor and a load during operation. The method comprises the steps of initiating at least one test sequence, and sending a signal indicating an error if said at least one test sequence indicates that the serviceability of the transmission part is not acceptable and if no further test sequences are to be performed. Additionally, said at least one test sequence includes the steps of setting a rotation speed of the electric motor at a test rotation speed, which differs from the rotation speed of the electric motor immediately prior to said setting, and measuring at the electric motor, within a period starting from the setting of the rotation speed of the motor and ending when the rotation speed of the electric motor has reached the test rotation speed.

Abstract: A control system, method for control, and control software for operating a startup shift element of an automated motor vehicle transmission or automatic transmission capable of electro-hydraulic or electro-pneumatic actuation with an electronic transmission control device, whereby the startup shift element may be shifted hydraulically or pneumatically in emergency mode even if the electronic control device fails. The control system includes a transmission-independent control module, and a emergency-operation mode shift valve capable of electrical triggering, that controls the hydraulic or pneumatic actuation device of the startup shift element. If the transmission-independent control module fails during transmission emergency-mode operation, the startup shift element is capable of actuation by means of the electrical triggering of the emergency-operation mode shift valve via the transmission-independent control module. This may particularly control a motor-vehicle startup procedure.

Abstract: A shift control system for a vehicle automatic transmission includes a vehicle speed sensor for detecting a vehicle speed, and a first control means normally performs a shift control of the transmission so that a target speed ratio of the transmission is achieved, which is determined based at least on a vehicle speed detected by the vehicle speed sensor. The shift control system further includes a second control means that properly performs shift control of the transmission when the vehicle speed sensor is in trouble, by generating a command for holding or changing a current speed ratio based on an input rotation speed of the transmission and/or driver's accelerating or decelerating operation of the vehicle.

Abstract: In a transfer drive mode switching control system employing a shift actuator that switches from one of a plurality of drive mode positions of a transfer to the other, a drive mode position sensor is provided to detect the drive mode position switched by the shift actuator and to generate information regarding the drive mode position. A transfer control unit outputs a control command signal based on the drive mode position information to the shift actuator for controlling switching between the drive mode positions responsively to a driver-selected drive mode. The transfer control unit allows only a switching operation between predetermined two different drive mode positions corresponding to both ends of a working range of the shift actuator at which motion of the shift actuator is stopped mechanically, in presence of a failure in the drive mode position sensor.

Abstract: A system for controlling a component of a gear in a vehicle, especially a clutch, through a hydraulic transmission link. The system includes a transmission control unit and an engine control unit, whereby a loss in fluid in the transmission link can be detected or a hazardous situation caused by the potential for fluid loss is avoided, whereupon the engine and/or the transmission can be suitably controlled using the transmission control and/or engine control unit.

Abstract: In a case of an electric failure caused to a traveling vehicle and when any of forward gears is held at a step S5, a comparison is made between: 1) a supposedly-engaged friction element of friction elements which is supposed to be engaged at the any of the forward gears and 2) an actually-engaged friction element of the friction elements which is sensed to be actually engaged, the sensing being based on a switch signal from a first hydraulic pressure switch 11, a second hydraulic pressure switch 12, a third hydraulic pressure switch 13, a fourth hydraulic pressure switch 14 and a fifth hydraulic pressure switch 15. When the supposedly-engaged friction element is not in accordance with the actually-engaged friction element, an electric system is determined to be in failure. In the case of the electric failure, a routine moves to a step S6 and subsequent steps for sticking the gear of an automatic transmission to a given gear.

Abstract: A clutch engagement control device controls the engagement of a forward clutch (32) and reverse clutch (33) in an automatic transmission connected to an engine (70) in a vehicle. An inhibitor switch (56) outputs a range signal in accordance with a position range of a select lever (51). A manual valve (57) supplies oil pressure selectively to one of the forward clutch (32) and the reverse clutch (33) by changing position in accordance with the position range of the select lever (51). A controller (60) of the clutch engagement control device determines whether an unmatching range condition occurs in which the range of the select lever (51) indicated by the range signal and the range of the manual valve (57) do not match, when the range of the select lever (51) indicated by the range signal is a drive range or reverse range; and suppress an increase in engine rotation speed prior to engagement of the forward clutch or reverse clutch when the unmatching range condition occurs.

Abstract: A method of controlling the hydraulic actuation of the clutches and the synchronizers in a dual clutch transmission in the event of a clutch or synchronizer fault. The method includes the steps of determining which clutch is faulted when a clutch-on fault is detected, then commanding an interruption of engine torque to the faulted clutch and a neutralization of all synchronizers of the same axis shaft as the faulted clutch. The method further senses if a synchronizer actuator-on fault has occurred, then determines which synchronizer is faulted if an actuator-on fault has is detected. The method steps further include preventing the further actuation of the other synchronizers on the same axis shaft as the faulted actuator.

Abstract: To avoid damaging the electrical braking system of a motor vehicle due to driving with an applied parking brake, the parking brake is automatically released, if the speed of the motor vehicle exceeds a prescribed minimum value, and the drive unit of the motor vehicle is driven in a specific operating state, and at least one operating element (e.g. gas pedal, gear shift lever, clutch pedal, safety belt, etc.) of the motor vehicle has been actuated by the driver of the motor vehicle. Sensor signals of sensors that sense the state of the above parameters are subjected to a plausibility check.

Abstract: A device to allow for emergency operation of an automatic-transmission motor vehicle, having a monitoring device to monitor pre-determined operating parameters, a diagnostic device to detect faults, a control device to activate an alternative function, and an output device by means of which the fault may be presented to the driver. The control device provides the driver an emergency operation capability while providing an alternative function depending on the degree of the fault.

Abstract: One embodiment of the present invention is an apparatus including an internal combustion engine for powering a ground travelling vehicle, a throttle control arrangement including a device for sensing position of an operator-adjustable pedal to provide a throttle control signal, a first sensor to sense rotational speed of the engine, a second sensor to sense brake status of the vehicle, a way to determine failure of the throttle control signal, and a way to operate the engine in a limp-home mode in response to the failure, which includes fueling the engine during the limp-home mode of operation in accordance with idle position of the pedal, rotational speed of the engine, and the brake status.

Abstract: A switching valve is provided which operates hydraulic friction engaging elements in a combination to establish a fifth speed “5th” when in a first position, and in a combination to establish a third speed “3rd” when in a second position, when a first electromagnetic valve to a fifth electromagnetic valve fail so as to stop operating. As a result, in the event of failure while driving, the fifth speed “5th” is first established to enable the vehicle to continue running. Then, when the position of a manual valve is changed by an operation by the driver when the vehicle is stopped or the like, the switching valve shifts a transmission into the third speed “3rd”, which has a larger gear ratio than the fifth speed “5th”, to ensure the driving force required to take off again.

Abstract: A control system and method for controlling a vehicular automated transmission system having an internal combustion engine and a multiple speed transmission, is provided. The control system includes an ignition having an output that issues an ignition signal and a first control unit that operates the engine in response to receipt of the ignition signal. A second control unit receives input signals from various system sensors and process the signals according to logic rules to issue a command output signal. A relay interrupts transmission of the ignition signal to the first control unit in response to either the absence or receipt of the command output signal. The method includes the steps of determining if the automated transmission system is operating abnormally and interrupting transmission of the ignition signal to the first control unit when it is determined the automated transmission system is operating abnormally.

Abstract: In an abnormality detecting device and method for a vehicular hydraulic pressure control circuit, which determines an abnormality that has occurred in a hydraulic pressure control circuit including an electromagnetic control valve which generates hydraulic pressure corresponding to a signal supplied from an electronic control unit, and a hydraulic switch which is turned ON when the hydraulic pressure generated by the electromagnetic control valve is equal to or higher than a predetermined value, a power supply of the electronic control unit is kept ON for a predetermined time after an ignition switch is turned from ON to OFF, and an abnormality that has occurred in the hydraulic pressure control circuit is detected within the predetermined time. Thus, it is possible to reliably detect an abnormality that has occurred in the vehicular hydraulic pressure control circuit.

Abstract: A vehicular transmission system is disclosed that includes a prime mover, a transmission having at least one mode of operation where the transmission is selectively shifted into a lower gear ratio as vehicle speed decreases, a master friction clutch for drivingly connecting the prime mover to the transmission, and at least one control unit. The control unit includes logic rules that selectively prohibit the transmission from being shifted into a lower gear ratio in response to a system operating condition during the at least one mode of operation. The system also includes at least one input corresponding to a system operating condition and at least one output corresponding to a command to prohibit the transmission from being shifted into a lower gear ratio in response to the sensed system operating condition. A control system and method for operating the vehicular transmission system are also disclosed.

Abstract: Within the scope of a load reduction method of automatic transmissions or clutches of a motor vehicle during emergency program shifting operations, an engine torque reduction is carried out during the emergency program shifting operation from a normal shifting program to an emergency program (NP).

Abstract: A judging section judges whether or not ranges detected, respectively, by a first range detection section consisting of a first detection section and a position detecting sensor, and a second range detection section consisting of a second detection section; a C1 detecting sensor and a B1 detecting sensor are in mutual agreement, and when the detected ranges are not in mutual agreement, a failure judging section judges a failure of the first range detection section.