A method for uncovering an electronic control unit ,ECU, to message identification, MID, mapping, comprising the steps of identifying, by processing circuitry coupled to a communication bus, a first message from a plurality of messages transmitted on the communication bus as a low priority message; determining, by the processing circuitry, whether the low priority message and a second message from the plurality of messages originated from a first electronic control unit, ECU, coupled to the communication bus, the second message being a higher priority message than the low priority message; and associating, by the processing circuitry via an ECU message identification, MID, set, an MID of the low priority message and an MID of the higher priority message to the first ECU; and wherein the determining whether the low priority message and the higher priority message originated from the first ECU comprises: issuing at least one controlled message error on the communication bus against the low priority message to force the low priority message to be retransmitted to cause an overlap between transmission of the low priority message and the higher priority message; determining whether, responsive to the overlap, the higher priority message was delayed by the low priority message; and determining that the low priority message and the higher priority message did originate from the first ECU based on a determination that the higher priority message was delayed by the low priority message. identifying, by processing circuitry coupled to a communication bus, a first message from a plurality of messages transmitted on the communication bus as a low priority message; determining, by the processing circuitry, whether the low priority message and a second message from the plurality of messages originated from a first electronic control unit, ECU, coupled to the communication bus, the second message being a higher priority message than the low priority message; and associating, by the processing circuitry via an ECU message identification, MID, set, an MID of the low priority message and an MID of the higher priority message to the first ECU; and wherein the determining whether the low priority message and the higher priority message originated from the first ECU comprises: issuing at least one controlled message error on the communication bus against the low priority message to force the low priority message to be retransmitted to cause an overlap between transmission of the low priority message and the higher priority message; determining whether, responsive to the overlap, the higher priority message was delayed by the low priority message; and determining that the low priority message and the higher priority message did originate from the first ECU based on a determination that the higher priority message was delayed by the low priority message. issuing at least one controlled message error on the communication bus against the low priority message to force the low priority message to be retransmitted to cause an overlap between transmission of the low priority message and the higher priority message; determining whether, responsive to the overlap, the higher priority message was delayed by the low priority message; and determining that the low priority message and the higher priority message did originate from the first ECU based on a determination that the higher priority message was delayed by the low priority message. <EOS>