Вот електросхема CAN, может чем то паможет
Diagram_BMW+E53+CAN-bus+instrument+med+IKE+instrument.pdf
Diagram_BMW+E53+CAN-bus+K+med+basis+instrument.pdf
Diagram_BMW+E53+CAN-bus+K+med+IKE+instrument.pdf
Diagram_BMW+E53+CAN-bus+PT+M54-M62-M57D30+motor-9.03.pdf
Diagram_BMW+E53+CAN-bus+PT+M54+motor+9.03-.pdf