| 摘要 |
The invention relates to a security device 17 for a vehicles electronic system. The vehicles electronic system comprises a Control Area Network (CAN) Bus 5 connected to a plurality of engine control units (ECUs) 8 and an On-Board Diagnostics (OBD) plug 5. The ECUs are accessible from the OBD plug through the CAN Bus. The security device comprises an input port (21, figure 2) for connection to the OBD plug, and an output port (23) for connection to the CAN Bus. Communications to and from the CAN Bus and the OBD plug are routed through the security device. The security device comprises means to detect whether a valid ignition key has been presented in the vehicle and means to permit write communications to pass from the OBD plug to the ECUs via the CAN Bus on detection of a valid ignition key and prevent write communications from passing from the OBD plug to the ECUs via the CAN Bus in the absence of a valid ignition key. The detection of a valid ignition key may involve detecting a communication on the CAN bus from an immobilizer ECU to operate a fuel pump or to start an engine. |
