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 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 monitoring method and device for determination of a gear-stick position, a vehicle control unit, and a vehicle. The monitoring method for determination of a gear-stick position includes: acquiring a first actual gear-stick position and a first acceptable gear-stick position calculated by a functional layer; calculating a second actual gear-stick position according to a gear-stick position signal; determining whether the first actual gear-stick position and the second actual gear-stick position are consistent; in case that the first actual gear-stick position and the second actual gear-stick position are consistent, determining whether the first acceptable gear-stick position is valid; and in case that the first actual gear-stick position and the second actual gear-stick position are inconsistent or the first acceptable gear-stick position is invalid, controlling the vehicle to enter a safe state. The present application can ensure safe driving of a vehicle.

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 diagnosis device determines diagnoses one of primary and secondary board temperature sensors as abnormal, in response to a condition that a state in which a primary temperature sensor value and a secondary temperature sensor value deviate from each other by a predetermined value or more continues for a predetermined duration or more; performs torque limitation to limit a torque inputted from an engine to an automatic transmission, during driving in a predetermined travel section based on a predetermined condition, after the one of the primary and secondary board temperature sensors is diagnosed as abnormal; and performs transmission shift restriction to restrict shifting of the automatic transmission along with the torque limitation, in response to a condition that the one of the primary and secondary board temperature sensors continues to be diagnosed as still abnormal after the driving in the predetermined travel section is completed.

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.

Systems and methods are provided for controlling a transmission. An engine stop-start event may be allowed or denied based on one or more characteristics of the vehicle including the transmission.

A control device for an automatic transmission includes: a failure diagnosis section for diagnosing whether or not a failure has occurred in a shift control system of the automatic transmission; a fail-safe control section for fixing the automatic transmission into a predetermined gear position in response to confirmation of the failure of the shift control system of the automatic transmission; and an oil temperature rise regulation torque reduction control section for outputting a torque reduction request to suppress torque of a vehicle driving source, based on temperature of transmission operating oil of the automatic transmission, and outputting the torque reduction request in response to satisfaction of an oil temperature condition that is set lower in oil temperature when the automatic transmission is fixed in a first gear position by the fail-safe control section than when the automatic transmission is not fixed in the first gear position.

A PWM control part rotationally drives a motor based on a PWM control value. A rotation speed control part controls a rotation speed of the motor. A rotation angle detection part detects a rotation angle of the motor. A reference position learning part controls the motor to rotate at a constant rotation speed until a detent plate stops at a limit position of a movable range and learns a reference position of the motor. A current detection circuit detects a current value corresponding to a driving current. A current limitation part limits a current supplied to the motor. A PWM control value limitation part controls the PMW control value to be equal to or smaller than a PWM limitation value, which is a predetermined value. A relation check part checks whether a relation between a current value detected by the current detection circuit and the PWM control value is inappropriate.

A method for monitoring a fixed-gear transmission includes deriving a node speed relationship for each of the planetary gear sets based upon a center distance and a gear ratio and determining equivalent speed parameters for nodes of the planetary gear sets based upon a transmission input speed state, an intermediate node speed state and a transmission output speed state. A clutch slip speed relationship is determined for each of the clutches based upon the node speed relationships for the planetary gear sets and the equivalent speed parameters for nodes of the planetary gear sets. Rotational speed sensors monitor the input transmission speed, the intermediate node speed and the transmission output speed. A clutch slip speed for each of the clutches is determined based upon the respective clutch slip speed relationship and the monitored input transmission speed, the monitored intermediate node speed and the monitored transmission output speed.