Patent ID: 6931924

Claim:
A calibration method for testing the function of an electrohydraulically controlled automatic transmission upon a test bench by simulating a vehicle operation, comprising the steps of: connecting an input shaft of the transmission with a driving source having preset rotational speeds and load ratios; connecting an output shaft of the transmission with a stationary torque-measuring hub that is separate from the transmission and that is mounted to a fixed part of the test bench and that blocks the output shaft; and individually testing each of a plurality of shifting elements existing in the transmission in succession to determine a characteristic quantify of each shifting element, including actuating each shifting element being tested while others of the shifting elements remain closed and determining the characteristic quantity of the shifting element being tested upon detecting a slip of the shifting element or a decrease of a slip of the shifting element, including providing an input rotational speed to the transmission to supply pressure-setting elements in the transmission with hydraulic pressure sufficient to actuate each shifting element being tested out of an opened condition to the extent necessary to determine, indicate and store a desired shifting element characteristic.