Patent ID: 8311715

Claim:
A method of using an electronic control device for detecting and responding to a transmission error in one of an automatic motor vehicle transmission and an automated motor vehicle transmission, the transmission having a starter element and being in one of a preset neutral position and a parking position, the transmission being connected to a drive motor of the motor vehicle via the starter element, the starter element being either a torque converter or a hydrodynamic clutch, the method comprising the steps of: determining, via the electronic control device, a current transmission rotational input speed when the motor vehicle is at least substantially motionless and the transmission is in one of a preset neutral position and a parking position; determining, via the electronic control device, a current engine rotational speed of the drive motor when the motor vehicle is at least substantially motionless and the transmission is in one of the preset neutral position and the parking position; calculating, via the electronic control device, a speed ratio as the ratio of the current transmission rotational input speed to the current engine rotational speed; providing a preset ratio threshold value of one of equal to 1 and less than 1; comparing the speed ratio with the ratio threshold value; and if the speed ratio is less than the ratio threshold value, then determining, via the electronic control device, that an error is present in the transmission; and initiating responsive measures in at least one of the transmission and the motor vehicle if the presence of an error in the transmission is determined.