Desired is a control device for a vehicle drive apparatus capable of determining an engagement failure in an engagement device when shifting a transmission device to a neutral state and making the rotational speed of a driving force source reduced. In order to shift a transmission device from a state in which an object shift speed is established and the vehicle is traveling to a neutral state in which no shift speed is established in the transmission device (#02), when an object engagement device is disengaged while maintaining engagement of a non-object engagement device and the rotational speed of a driving force source (#04, #06) is made to be reduced, an engagement failure in the object engagement device (#02, #07) is determined based on a change in the rotational speed of an input member.

Disclosed is a method of diagnosing a malfunction in a dual clutch transmission (DCT) attributable to a gear synchromesh failure, without an output shaft speed sensor. The method includes: calculating, a difference (referred to as a first difference) between a first input shaft speed and the product of a wheel speed and a first gear ratio; a difference (referred to as a second difference) between a second input shaft speed and the product of a wheel speed and a second gear ratio; diagnosing a first input shaft as having a transmission gear synchromesh failure when the first difference is greater than a first reference value and the second difference is equal to or smaller than a second reference value; and performing control such that a gear shifting operation is performed using only a second input shaft when the first input shaft is diagnosed as having a transmission gear synchromesh failure.

An actuator diagnostic apparatus is provided for an electronic control unit of a vehicle. The actuator diagnostic apparatus of the electronic control unit for a vehicle is characterized by containing: a high-side driver which drives an actuator from a high-side; an output voltage sensing unit which senses an output voltage of the high-side driver; a low-side driver which drives the actuator from a low-side; a pull-down switch which pulls down an input voltage of the high-side driver; a shutdown driver which actuates the pull-down switch; and a diagnostic control unit which diagnoses shutdown of the actuator upon receiving an input of the output voltage from the output voltage sensing unit after respectively actuating the high-side driver, the low-side driver, and the shutdown driver in accordance with a shutdown diagnosis order.

A malfunction part sensing device for an automatic transmission for a vehicle which is arranged to attain a plurality of shift stages by selectively engaging a plurality of frictional engagement elements, the malfunction part sensing device includes: a shift stage monitoring section configured to monitor the shift stages before and after the shift of the automatic transmission; a malfunction sensing section configured to sense the malfunction mode from a behavior of the vehicle which is generated in accordance with the malfunction; and a malfunction part limiting section configured to limit the one of the frictional engagement elements in which the malfunction is generated, based on the malfunction mode and a shift manner by a combination of the shift stages before and after the shift.

A shift device mounted on a vehicle includes a motor configured to drive, by electric power supplied from a power supply mounted on the vehicle, a shift switching member configured to switch shift positions, a cut-off unit configured to cut off conduction of a power supply line through which the electric power is supplied to the motor, and a drive circuit unit configured to output the electric power to the motor and including a driving switching element configured to execute a switching operation. The shift device is configured to determine an abnormality of the power supply line when a voltage of the power supply line is smaller than a predetermined threshold value, turn off the driving switching element, and cut off the conduction of the power supply line by the cut-off unit.

A power supply controller includes a driver having a circuit board and controlling an operation of an electric oil pump, a control unit controlling power supply to the driver, a board temperature sensor detecting a temperature of the circuit board; and an oil temperature sensor detecting a temperature of a working oil of a transmission as an oil temperature. The control unit executes energization prohibition control for prohibiting power supply to the driver when the temperature of the circuit board detected by the board temperature sensor exceeds a predetermined first threshold temperature, and executes cancellation determination for determining whether to cancel the energization prohibition control based on the oil temperature detected by the oil temperature sensor during execution of the energization prohibition control.

A method and a system of diagnosing a vehicle oil leak are capable of detecting an oil leak state of transmission oil on the basis of logic. The method includes an operating condition determination step of determining, by a controller, whether a minimum operating condition of a vehicle is satisfied. The minimum operating condition is required to normally generate a target line pressure by operating an EOP. The method includes a counting step of counting, by the controller, an operating time of the EOP when the minimum operating condition is satisfied and includes an oil leak diagnosis step of diagnosing, by the controller, an oil leak when the counted continuous operating time of the EOP is a permissible time or more.

A hydraulic control apparatus including a first and second control valves switched to exert hydraulic pressure on a piston to press toward first position, a third and fourth control valves switched to exert hydraulic pressure on the piston to press toward second position and, a CPU. The CPU performs executing a first process controlling the control valves so that hydraulic pressure is exerted by switching of the first, second and third control valves or a second process controlling the control valves so that hydraulic pressure is exerted by switching of the second control valve and determining that the first control valve is failed when movement of the piston to the first position is not detected through the first process and determining that the third control valve is failed when movement of the piston to the first position is not detected through the second process.

A motor angle calculation unit acquires from a motor rotation angle sensor a motor rotation angle signal corresponding to a rotational position of the motor, and calculates a motor angle based on the motor rotation angle signal. An output shaft signal acquisition unit acquires, from an output shaft sensor that detects a rotational position of an output shaft, an output shaft signal corresponding to the rotational position of an output shaft. An abnormality determination unit determines abnormality in the output shaft sensor. A target angle setting unit sets a target rotation angle corresponding to a target shift range. A drive control unit controls driving of the motor so that the motor angle becomes a target rotation angle. The target angle setting unit sets the target rotation angle to different values when the output shaft sensor is normal and when the output shaft sensor is abnormal.

Methods and systems are provided for controlling and diagnosing one or more clutches in a transmission. In one example, a method for operation of a vehicle system is provided that includes at a diagnostic controller or processing unit independent from a driveline controller or processing unit, respectively, determining an engagement state of a clutch in a transmission of the vehicle system, wherein the engagement state is selected from a group of three or more clutch engagement states. The method further includes identifying an unauthorized clutch state based on the engagement state of the clutch and a speed of the vehicle and responsive to the identification of the unauthorized clutch state, operating the vehicle system in a fault state.