In an embodiment of a vehicle, the vehicle comprises: a vehicle network bus; one or more electronic control units coupled to the bus. One electronic control unit comprises: a processor; a memory; an interface to the vehicle network bus; and an intrusion detection program stored in the memory and executable by the processor. The processor utilizes the interface to monitor data on the vehicle network bus and utilizes the intrusion detection program to detect one or more anomalies in the monitored data. The electronic control unit generates an alert upon detection of one or more anomalies.