Porsche 991 Nav System Dead: Fix Tips & Mechanic Hunt

Hey there, I had a similar issue with my 2015 Porsche Cayman S last year. The navigation system went completely dead, though the screen would power on. Turned out to be a CAN BUS communication failure between the PCM (Porsche Communication Management) and other control modules. Took it to a certified Porsche specialist who diagnosed it properly. They had to repair some damaged wiring in the CAN BUS system, apparently, some wires had deteriorated near the driver's side door hinge. It was definitely a serious issue that required specialized diagnostic equipment and expertise. The repair wasn't just a simple plug-and-play fix, they had to trace the exact location of the communication break and repair the wiring harness. After the repair, they had to reconfigure the whole system to get everything talking again. If you're in this situation, I'd strongly recommend going to a Porsche certified shop. Generic mechanics often lack the specific diagnostic tools needed for these complex communication systems. Best of luck with the repair.

Thanks a lot for sharing your experience! It's really helpful to know what I might be dealing with. How much did you end up paying for the whole repair job? And has everything been working smoothly since they fixed it? Just wondering if any other electrical gremlins popped up afterward.

Hey again! Happy to give you an update! After getting it fixed, everything has been working perfectly, not a single glitch since then. The total bill came to 235€ for fixing the CAN BUS problem, which was actually less than I initially feared. The mechanic told me there was some damage in the MOST bus system that needed sorting out. Since the repair, the "Message error between control devices" that was driving me nuts has completely disappeared. The nav system is back to working like new, and honestly, it was worth every penny. I'm really glad I went with a certified Porsche specialist, these guys really know their stuff when it comes to these complex electrical systems. Just a heads up, I haven't had any other electrical issues pop up afterward, which is a huge relief. The car's been running like a dream for the past year. If you end up having the same issue, definitely go with a proper Porsche specialist. Sure, they might be a bit pricier than a regular mechanic, but they'll get it right the first time! Let me know if you need anything else!

Thanks so much for all the details! I actually took your advice and went to a certified Porsche specialist yesterday. You were spot on about the CAN BUS issue, that's exactly what was wrong with mine too! The mechanic was super professional and fixed it right away. Cost me about 280€, which wasn't too bad considering what I was expecting. The best part? My nav system is working perfectly now! They also did a quick check of other systems while they were at it, just to make sure there weren't any other issues lurking around. Honestly, I'm kicking myself for not going to a Porsche specialist sooner. Was so worried about getting ripped off that I almost made things worse by going to unusual mechanics. Really appreciate you sharing your experience, it definitely helped me make the right decision. Time to enjoy some proper navigation in my 991 again! Thanks everyone for the help!