VW T-Cross Audio & Nav System Failures Traced to MOST Bus

I had a similar issue with my 2021 VW T-Roc. As someone with moderate experience in car diagnostics, I can relate to this frustrating situation with the infotainment system. The symptoms were nearly identical, complete audio failure and navigation system not responding. After running diagnostics, the workshop confirmed a defective control unit in the MOST bus network, which was disrupting data transmission between components. The repair involved: 1. Complete diagnostic scan of the car bus network 2. Testing individual control units 3. Replacing the faulty control unit 4. Reprogramming and coding the new unit 5. Final system test to ensure proper data transmission Total repair cost was 1000€ including parts and labor. The issue never returned after the fix. To provide more specific guidance about your T-Cross situation, could you share: Complete fault codes from diagnostics, Whether other electrical systems are affected, If the issues started suddenly or developed gradually, Current software version of your infotainment system These details would help determine if your automotive protocol issues match what I experienced with my T-Roc.

Latest service was at 133000km. Thanks for the detailed response. After scanning the vehicle again with my OBD reader, I noted other symptoms that might help diagnose this: The fiber optics connection seems intermittent, as the system occasionally works for a few seconds before failing. The bus network diagnostic shows error code 00288 suggesting a communication timeout between modules. I checked the infotainment software version, its still running 0.5.1 from factory. The issue developed gradually over about 2 weeks, starting with occasional audio dropouts before complete failure. Your repair path sounds similar to my situation. Did you notice any warning signs before the complete system failure? Were there any temporary fixes that helped before the full repair? Before booking a workshop appointment, I want to ensure Im targeting the right components, as 1000€ is a significant investment.

Thanks for those additional details about your T-Cross issue. The gradual failure pattern you described matches my experience exactly, those initial audio dropouts are a classic sign of failing MOST bus components. Before my system failed completely, I noticed brief flickering of the infotainment display and unusual reconnection sounds from the audio system. The intermittent fiber optics connection you mentioned was also present in my case, and that error code 00288 is very familiar, it was logged in my car electronics system too. A temporary workaround that helped occasionally was to: 1. Power down the entire car electronics system 2. Wait 2 minutes 3. Restart the vehicle 4. Let the control units reinitialize However, this only provided brief relief as the bus system would eventually fail again. The repair cost was significant, but trying cheaper fixes first actually risked damaging other connected control units in my case. The automotive protocol diagnosis showed the fiber optic ring was compromised, causing those timeout errors. Given your identical symptoms and error codes, I strongly suspect the same root cause in your car bus network. The outdated software version 0.5.1 should also be updated during repair, though this alone wont fix the hardware fault.

Based on all the feedback, I need to proceed with a proper diagnosis. The communication timeout error 00288 and matching symptoms with your case strongly suggest a MOST bus fault in my T-Cross. The deteriorating pattern over 2 weeks matches your experience perfectly. I tried your suggested temporary fix with the full system power down and restart. While it briefly restored functionality, the bus system failed again within an hour. The car diagnostics clearly point to the fiber optic connection being the core issue. Will schedule an appointment with a workshop that specializes in car electronics. The 1000€ repair cost seems reasonable given the complex nature of replacing and reprogramming the control unit. Having the outdated infotainment software updated during the repair makes sense too. Really helpful to know that attempting cheaper fixes first could potentially damage other components in the bus network. Will proceed with the full repair to avoid causing additional issues with connected control units. Will update once the repair is completed. Thanks for helping me understand the exact nature of this bus system failure.