Electronic control unit for vehicle

An electronic control unit for a vehicle, comprising:

• a vehicle identification information storing part that stores therein vehicle identification information, which is unique on a vehicle-by-vehicle basis;
• a first cross-check information storing part that stores therein first cross-check information, which is unique on the vehicle-by-vehicle basis and different from the vehicle identification information;
• a second cross-check information acquisition section that acquires second cross-check information, which is unique on the vehicle-by-vehicle basis, different from the vehicle identification information and stored in an external electronic control unit that is mounted in a same vehicle as the electronic control unit is mounted in;
• a cross-check information determination section that determines whether the first cross-check information matches the second cross-check information;
• and
• a stored information management section that manages a change of the vehicle identification information stored in the vehicle identification information storing part upon receiving an instruction for changing the vehicle identification information, such that:
• the stored information management section prohibits the change of the vehicle identification information when the cross-check information determination section determines that the first cross-check information matches the second cross-check information;
• and
• the stored information management section changes the vehicle identification information when the cross-check information determination section determines that the first cross-check information does not match the second cross-check information.