Method for unlocking parking lock of parking lock system of automatic transmission of motor vehicle, involves monitoring whether main hydraulic pressure supply is ready or started during starting operation of drive unit of motor vehicle

摘要

The method involves monitoring whether a main hydraulic pressure supply is ready or started or not ready or can not be started during a starting operation of a drive unit (1) of a motor vehicle. A normal release of a parking brake is triggered by using the main hydraulic pressure supply. A secondary hydraulic pressure supply is provided for emergency release of the parking brake. An independent claim is included for a control unit of a motor vehicle.