Audi A5 Brake Light Switch Mystery Finally Solved

Had the same brake light switch issue on my 2011 A4 2.0T. The electrical issue showed identical symptoms, intermittent brake light function and warning messages. The automotive switch failure is a known problem on these models. The repair needed two steps: First, diagnostic scanning confirmed the switch malfunction. Then, a complete switch replacement was required since these units cannot be repaired. The brake system itself was fine, just the switch sending incorrect signals. This is not a major repair but its crucial for vehicle safety. The switch connects directly to multiple systems including cruise control and brake light activation. Driving with a faulty brake light switch can cause unexpected system behaviors. The repair took about an hour once the parts arrived. Most important is using OEM parts for this fix, as aftermarket switches often fail prematurely. A proper garage will have the right diagnostic tools to verify the fix worked correctly. Worth noting that if left unfixed, it can trigger additional electrical issues with other connected systems over time.

Thanks for the detailed info on fixing the brake light switch. The symptoms sound identical to what my A5 was showing. Really helped me feel more confident about the diagnosis. Would you remember roughly how much you paid for the whole repair? Also curious if you had any other electrical issues pop up since getting it fixed? Just want to make sure I budget correctly and know what to watch out for.

It turned out the brake light switch itself was not faulty on my A4. The mechanic discovered it was simply a connection issue, some debris had gotten into the switch housing causing intermittent contact. A thorough cleaning resolved the electrical issue completely. The inspection and cleaning cost 0 Euro since it was just basic maintenance. No parts replacement was needed in my case. This was purely a personal error situation that could have been avoided with regular cleaning. The good news is I have not experienced any brake light problems or related electrical issues since that service visit. The tail light and all brake system functions have worked flawlessly. The warning messages also disappeared completely after the cleaning. Just make sure your mechanic thoroughly checks the switch connections before automatically replacing parts. Sometimes the simplest solution is the correct one when dealing with automotive electrical problems.

Thanks for the input. Took my A5 to a different shop this time and had a much better experience. The mechanic found the exact issue, just like the first reply suggested, it was the brake light switch giving false signals. Total bill came to 180 Euro including diagnostics and parts. Was worried it might be something bigger, so this was actually a relief. They used genuine parts and ran a full system check after the repair. The electrical issue cleared up right away, no more warning lights or problems with the tail light function. Been driving for a few weeks now without any issues popping up. Really glad I asked here first. Helped me walk in knowing what to expect and not get oversold on unnecessary repairs. The automotive switch replacement was straightforward, just like described. Definitely feeling more confident about this shop too, they took the time to explain everything and showed me the old part.