Electronic control unit

The present invention relates to an electronic control unit (2) comprising a first and a second computer (4, 6). The first computer (4) includes a first diagnostic means for diagnosing operation of the first computer by performing a diagnosis, in which a comparison is performed between a value calculated using a predetermined operation and a pre-stored reference value for determining whether a relationship between the calculated value and the pre-stored reference value is normal. The first computer further includes a data transmitting means for sending the calculated value and the pre-stored reference value used for the diagnosis performed by the first diagnostic means. The second computer (6) includes a receiving means for receiving the calculated value and the pre-stored reference value, and further includes a second diagnostic means for determining whether the first diagnostic means normally operates based on a comparison between the calculated value and the pre-stored reference value received by the receiving means.