After rectifying an abs fault on a new customers Q7 she asked us to investigate a long standing fault with the MMI system, namely apart from a brief illumination of the screen nothing functioned at all.
We began by connecting the Autologic Assist in order to communicate with the various modules associated with the media system, though we could communicate with all the modules numerous error codes were present in various modules.
The next step was to carry out a fault clear broadcast which clears all the error codes in one operation. Once complete we attempted to switch on the MMI and as expected the system still displayed the fault.
We then carried out a loop break diagnostic check, this test checks the integrity of the electrical/optical loop on the media system. The test immediately displayed an optical fault within the sound system module, the likely cause is a fault within the module but to be sure the optical plug was removed from the module (located in the O/S/R of the vehicle) and connected to the emulator (see photo).
Upon switching on the MMI everything now functioned minus the sound of course. As a new sound module (bose) is around £900 + vat the customer opted to have the original unit repaired. The repaired unit was re-installed and component protection de-activated.
The repaired unit functioned perfectly and the vehicle was returned to the owner who was happy to have her audio working again.