CONTROLLER AREA NETWORK BUS MONITOR

Techniques for monitoring a controller area network bus are described herein. In one example, a system comprises a processor that is to detect a message from a source electronic control unit in a vehicle and calculate a location of the source electronic control unit based on at least two arrival times, the arrival times indicating a distance between a first monitor and the source electronic control unit. The processor can also detect that the message corresponds to a function controlled by a second electronic control unit and generate a warning that the message from the source electronic control unit is malicious.