Method for securing the time synchronization in a server ECU

A method for securing time synchronization in a server electronic control unit (ECU), in which a time synchronization takes place according to a time synchronization standard, comprising:

• initializing the time synchronization of components of the server ECU;
• storing a unique clock identification of a grandmaster clock determined during the initialization in each of the components of the server ECU that does not provide a previously determined grandmaster clock;
• identifying a shadow controller selected from the components of the server ECU;
• transmitting synchronization messages;
• querying a sending time with the shadow controller;
• inserting a time in a follow-up message by way of the shadow controller that forms the grandmaster clock, and retransmitting the time;
• and
• sending additional messages relating to time synchronization by way of selected network devices that do not provide the previously determined grandmaster clock,
• wherein information sent in the additional messages relating to time synchronization and also to clock parameters relevant for determining a best clock by a Best Master Clock Algorithm (BMCA) and a domain number match those of the previously determined grandmaster clock, or are comparable with them, and
• wherein the additional messages relating to time synchronization contain a unique clock identification corresponding to the identification of a respective selected network device.