The present invention relates to a method for operating a control unit for controlling or regulating a function of a motor vehicle. The control unit includes a programmable memory device. The control or regulation is realized by executing a computer program (P0) at least partially stored in the memory device and by using data (D0) stored at least partially in the memory device. In order to offer the most efficient protection against manipulation of the contents of the memory device by an unauthorized person, it is provided that, at least following a modification of the computer program (P0) stored in the memory device or of the data (D0) stored in the memory device, the modified computer program (P1) is executed only and/or the modified data (D1) are used only if the modified computer program (P1) and/or the modified data (D1) has/have been successfully verified.