RS6 Electronics Gone Haywire After Service Visit

Had similar issues on my 2019 RS4 with the same 4.0L engine. The car electronics were showing unusual warnings and the infotainment system would frequently restart. After multiple diagnostic checks, it turned out Transport Mode was indeed activated during routine maintenance. Transport Mode typically activates when service work is performed, limiting various vehicle functions to conserve power. The issue required a proper software update and system reset at an authorized service center. The root cause was traced to a corrupted control module that was triggering false warnings. This is considered a serious electrical system issue since it affects multiple vehicle functions and safety systems. The fix involved: Full system diagnostic scan, Control module reset and recoding, Software update to the latest version, Deactivation of Transport Mode, Battery voltage check and system calibration Would strongly recommend getting a professional diagnostic check rather than attempting DIY solutions, as these automotive electrical issues can cascade into more significant problems if not properly addressed. The high mileage suggests it could also be time for a comprehensive electrical system inspection.

Thanks for sharing your experience. That Transport Mode situation sounds exactly like what I dealt with on my RS6 a few months ago. The car electronics were acting up in the same way, especially with those unusual warning messages popping up. The immobilizer system kept going crazy too, and my key fob was working intermittently. Getting it fixed required a full software update and system reset, plus they found a faulty control module that needed replacement. Did the issues completely resolve after your repair? And if you remember, what was the total cost for the fix? Mine ended up running around 850 Euro for everything, but wondering if that was on the high side. Just want to make sure nothing else came up for you in the months after the repair.

After getting the vehicle settings corrected at the dealer, all issues were completely resolved on my RS4. The transport mode activation was indeed the root cause, triggering those electrical system warnings. The software update and system reconfiguration fixed everything, no unusual warnings, immobilizer works perfectly, and the car electronics are running smoothly. Since my car was still under warranty, the repair cost was 0 Euro. The service included a full system diagnostic, deactivation of transport mode, and a complete software update to ensure all control modules were properly configured. Its been 8 months since the fix, and no electrical issues have resurfaced. The car configuration is stable, and all systems are functioning as intended. Your repair cost of 850 Euro seems reasonable considering they had to replace a control module, which wasnt necessary in my case. The key is getting these electrical system issues addressed promptly by qualified technicians who understand the vehicle software architecture. Leaving them unchecked can lead to more complex problems down the line.

Thanks everyone for the helpful feedback. I finally bit the bullet and took it to a different shop last week. The diagnostic check confirmed what you all suspected, Transport Mode was stuck active, plus they found a damaged wiring harness near the trunk that was causing some of the electrical issues. Total bill came to 650 Euro for the software update, car configuration reset, and harness repair. The shop also cleaned up some corroded battery terminals while they were at it. My key fob works perfectly now and all those unusual warning messages have disappeared. Best part is the engine starts normally every time, no more of that weird hesitation. The nav system and other electronics are all working like new again. Really glad I didn't try fixing this myself since there were multiple issues involved. Still keeping an eye on things, but after a week of driving, everything seems solid. Definitely learned my lesson about getting electrical problems checked out right away rather than hoping they'll fix themselves.