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.

A motor sticking diagnosis and repair method includes the steps of, when an operation of a shift lever is detected, determining whether a current position matches a target position, when the current position does not match the target position, rotating the motor toward the target position, determining once again whether the current position matches the target position after rotation of the motor, when the current position does not match the target position, diagnosing whether the motor sticking has occurred, when the motor is diagnosed as being stuck, allowing the motor to switch to a free-rotation mode by temporarily blocking the current being applied to the motor upon sticking diagnosis, and selecting either a first repair strategy or a second repair strategy depending on whether the position of the motor changes after switching to the free-rotation mode.

In some implementations, a controller may cause a gearbox coupled to a rotor to shift between a first gear ratio and a second gear ratio one or more times. The controller may obtain a first set of position data that identifies respective first positions of a gear selector of the gearbox for each shift to the first gear ratio, and a second set of position data that identifies respective second positions of the gear selector of the gearbox for each shift to the second gear ratio. The controller may determine a first calibrated position of the gear selector for a shift to the first gear ratio based on the first set of position data and a second calibrated position of the gear selector for a shift to the second gear ratio based on the second set of position data.

An apparatus for diagnosing an automatic transmission for detecting abnormality during driving of a vehicle includes a G-sensor configured to measure a vibration signal including a longitudinal vibration signal, a status detection unit configured to obtain the vibration signal of the G-sensor and status data of transmission and engine sensors of the vehicle, and a controller configured to check an operational element for each shifting operation by using a current shift-stage, a target shift-stage, and a shifting time detected as the status data, measure the longitudinal vibration signal of the G-sensor to calculate fluctuation level of the longitudinal vibration signal for each operational element, and determine a shift shock event when a longitudinal vibration signal value after adjustment based on driving acceleration of the vehicle exceeds a reference value.

In some implementations, a controller may cause a gearbox coupled to a rotor to shift between a first gear ratio and a second gear ratio one or more times. The controller may obtain a first set of position data that identifies respective first positions of a gear selector of the gearbox for each shift to the first gear ratio, and a second set of position data that identifies respective second positions of the gear selector of the gearbox for each shift to the second gear ratio. The controller may determine a first calibrated position of the gear selector for a shift to the first gear ratio based on the first set of position data and a second calibrated position of the gear selector for a shift to the second gear ratio based on the second set of position data.

An apparatus for diagnosing an automatic transmission for detecting abnormality during driving of a vehicle includes a G-sensor configured to measure a vibration signal including a longitudinal vibration signal, a status detection unit configured to obtain the vibration signal of the G-sensor and status data of transmission and engine sensors of the vehicle, and a controller configured to check an operational element for each shifting operation by using a current shift-stage, a target shift-stage, and a shifting time detected as the status data, measure the longitudinal vibration signal of the G-sensor to calculate fluctuation level of the longitudinal vibration signal for each operational element, and determine a shift shock event when a longitudinal vibration signal value after adjustment based on driving acceleration of the vehicle exceeds a reference value.

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 controller drives a shifting actuator to move a first engagement member from an original position of a first engagement portion in one direction along a relative motion path and acquires first position information representing a first position, the first position being a position where the first engagement portion moved in the one direction contacts a second engagement portion. The controller drives the shifting actuator to move the first engagement member from the original position in the other direction along the relative motion path and acquires second position information representing a second position where the first engagement portion moved in the other direction contacts the second engagement portion. The controller calculates a center position of the first engagement portion on the relative motion path from the acquired first position information and the acquired second position information, compares the calculated center position to the original position.

A motor sticking diagnosis and repair method includes the steps of, when an operation of a shift lever is detected, determining whether a current position matches a target position, when the current position does not match the target position, rotating the motor toward the target position, determining once again whether the current position matches the target position after rotation of the motor, when the current position does not match the target position, diagnosing whether the motor sticking has occurred, when the motor is diagnosed as being stuck, allowing the motor to switch to a free-rotation mode by temporarily blocking the current being applied to the motor upon sticking diagnosis, and selecting either a first repair strategy or a second repair strategy depending on whether the position of the motor changes after switching to the free-rotation mode.

A transmission actuator for tractor includes: a motor which provides power; rails which are movable by operating the motor; a rail sensor which detects a neutral state of the rails; a position sensor which detects a movement displacement of the rails; and a rotation sensor which is mounted to the motor to detect the number of revolutions of the motor.