Possible cause of fault
- Ring break diagnosis line short circuit to B+/ground or open circuit
- The recipient MOST control unit is faulty
- PCM2 faulty
NOTE:
- The ring break diagnosis line is connected to the following MOST control units:
- PCM2 as of model year 2003
- PCM2 gateway
- PCM2 MMI
- PCM2 navigation (optional)
- The ring break diagnosis line and the MOST optical waveguide are connected to the following control units:
- External amplifier (Harman or BOSE) (optional)
- CD changer (optional)
- Telephone/telematics (optional)
Courtesy of PORSCHE OF NORTH AMERICA, INC.