Audi S3 Keyless Entry Fix: Bumper Antenna Guide

Had a similar issue on my 2012 Audi A3 with keyless entry. After struggling with inconsistent remote locking and starting problems, I took it to a workshop since I have only basic car maintenance experience. The automotive antenna system was indeed the culprit. The technician found damaged wiring connections to the antenna module in the front bumper area. The car radio and fm antenna connections were also checked during diagnosis since they share some wiring paths. The repair involved: Full diagnostic scan, Testing vehicle antenna signal strength, Replacing corroded connection terminals, Resealing the antenna housing Total repair cost was 95 Euro and resolved all keyless system issues completely. To provide more specific guidance for your S3: Could you share, Any error codes stored? When did symptoms first appear? Does the issue get worse in wet weather? Have you had any front end damage or repairs? This would help determine if your situation matches what I experienced with the antenna repair on my A3.

Have the same issues on my S3 (116445 KM). Had it serviced last month and the scan showed error code B103900. Started having these problems about 2 weeks ago right after a heavy rain. The car antenna mount seems corroded from what I can see. The keyless entry works maybe 1 out of 5 tries now, and remote start is completely dead unless I use the physical key. Good to hear your antenna replacement fixed similar symptoms. Will check with my regular shop about testing the signal strength and connections before committing to a full antenna system repair.

Thanks for those details about your S3. The symptoms you describe match my A3 situation exactly, especially the timing with the rain exposure. Signal interference from corroded antenna connections is a common failure point in these models. Since you mention visible corrosion on the car antenna mount, thats a clear sign. Our vehicle antenna setups are nearly identical, and water intrusion through a deteriorated mount seal was the root cause in my case. A few tips from my experience: The signal testing is crucial before replacing parts, Make sure they check all antenna module grounds, The repair shop should verify the keyless system firmware is current, Consider getting the entire mount assembly replaced if corroded My A3 has been flawless for 6 months since the antenna repair. Given your matching symptoms and error code, I strongly suspect youll have the same positive outcome. The 95 Euro I spent was well worth avoiding the constant frustration of unreliable keyless entry. Let us know what you find after the signal strength testing. Always good to confirm the diagnosis before spending money on antenna repairs.

Thanks everyone for the helpful antenna troubleshooting advice. Quick update, took it to the shop today and their diagnostic testing confirmed my vehicle antenna system is the problem. Signal strength was way below spec and they found water damage in the antenna housing, exactly as described. Going ahead with the full antenna replacement including new mount and seals. Parts and labor quoted at 110 Euro which seems reasonable based on the previous repair costs shared here. Really hoping this resolves both the keyless entry and remote start issues like it did for the A3. Will report back once the repair is done. Always good to document these fixes for others who might run into similar automotive antenna problems down the road. Appreciate all the detailed feedback that helped confirm I was on the right track with the diagnosis.