A method is provided for controlling a microcontroller in a control unit in a motor vehicle, having a processor core, at least one read-only memory area and at least one rewritable memory area, at least one control program which is intended to be processed by the processor core being stored in the rewritable memory area. In order to provide a method for controlling a microcontroller in a control unit that better protects the verification of memories of the microcontroller against unauthorized intervention, a verification program is stored in a write-once memory area of the rewritable memory area and a service program is stored in the read-only memory area. The verification program is called by the control program via the service program at regular intervals and verifies at least part of the rewritable memory area. In addition, the service program resets a counter. A RESET of the control unit is triggered by the verification program when manipulation of the verified memory area is detected or by the counter in the event of counter overflow.