Audi Q8 Brake Light Switch Issues & Error Warnings

Having some experience with electrical issues, I encountered a similar situation with my 2018 Audi Q7. The vehicle safety system displayed identical error messages regarding brake lights, despite them working properly. After initial panic about potential switch replacement costs, it turned out to be something quite simple. The brake light switch was functioning correctly, but the error messages appeared because of improper electrical contact. There was some dirt buildup around the brake pedal mechanism where the switch is located. The solution required no workshop visit. I simply cleaned the area around the brake pedal mechanism and switch with electrical contact cleaner, making sure to remove any debris. After cleaning, I pressed the brake pedal several times to ensure good contact. Then I disconnected the battery for about 15 minutes to reset the error messages. Total cost: 0 Euro. Before trying this though, it would be helpful to know: Have you checked for any visible dirt around your brake pedal? Did these messages appear suddenly or gradually? Have you had any recent brake-related work done? Does the brake pedal feel different than usual? This could help determine if you are experiencing the same relatively simple issue or if there might be a different underlying problem requiring professional attention.

Thanks for sharing your repair experience. The last service was at 34871 KM, and during inspection, they actually mentioned potential electrical issues but nothing specific about the brake system. The brake light warning appeared suddenly after driving through heavy rain. The brake pedal feels normal with no changes in pressure or responsiveness. No recent brake work has been done. I checked around the brake pedal area and noticed some moisture, which might be related to the automotive switch problems. After reading your solution, I will try cleaning the brake light switch area first before considering more expensive repairs. The electrical contact cleaner seems like a smart first step to address these error messages before visiting a workshop.

Thanks for providing those additional details. Your description of the moisture after heavy rain strongly supports my initial suspicion about contact issues. This matches exactly what I experienced with my Q7, water intrusion can create these exact symptoms in the brake light switch area. For the cleaning process, I recommend using a high-quality electrical contact cleaner that leaves no residue. After dealing with my brake system issue, I also applied some dielectric grease around the switch housing to prevent future moisture-related problems. The vehicle safety warnings disappeared completely after this treatment. Since your brake lights are still functioning and the pedal feels normal, this suggests the core brake system is working properly. The error messages in the infotainment system are likely triggered by poor electrical conductivity rather than a genuine brake light failure. Quick tip from my experience: after cleaning, try cycling the ignition a few times while pressing the brake pedal. This helped my Q7s computer system recognize the restored connection. If the error persists after cleaning and battery reset, then it might be worth getting the switch tested professionally.

Thanks for the detailed suggestions. I will get both the electrical contact cleaner and dielectric grease to tackle this issue. The connection between the heavy rain and the sudden appearance of error messages makes perfect sense now. I plan to disconnect the battery, clean the brake light switch area thoroughly, apply the dielectric grease as suggested, and then reset the system. Your tip about cycling the ignition while pressing the brake pedal is particularly helpful, I will definitely try that after cleaning. If these steps dont resolve the electrical issue and the brake light warnings persist, I will have a professional check the automotive switch. But given how similar our situations are, especially with the moisture exposure, I am hopeful this DIY solution will fix the problem. Will update once I complete the cleaning process. The fact that the actual brake system and brake lights are working normally gives me confidence this is just an electrical contact issue rather than a serious brake light switch failure.