An electronic control unit is provided for installation in a vehicle. The electronic control unit is operable to provide intrusion detection for the vehicle electronic systems. The electronic control unit comprises: a processor; a memory; and an interface to a vehicle network bus coupled to vehicle electronic control units. The processor utilizes the interface to monitor data on the vehicle network bus. An intrusion detection program is stored in the memory and is executable by the processor. The processor 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.