Audi Q3 Keyless System Failure Points to Bumper Antenna

Having some experience with car electronics, I encountered a similar issue with my 2018 Audi Q5. The symptoms matched yours exactly, keyless entry stopped working and remote locking became inconsistent. The problem turned out to be signal interference caused by damaged wiring connecting to the antenna mount in the front bumper area. The workshop diagnosed it as a cable connection issue where the wiring had become corroded and was interrupting the radio signal between the key and the car. The repair involved: Complete diagnostic scan, Removal of front bumper trim, Antenna replacement and wiring harness check, System reset and testing Total cost was 95 Euro for parts and labor, and it completely resolved the issue. The car radio was also affected occasionally before the fix, which makes sense given the antenna connectivity problem. Before suggesting specific solutions, could you share: Are there any warning lights on the dashboard? Does the key fob battery have good charge? Have you noticed if the issues get worse in wet weather? Were there any recent repairs in the bumper area? This information would help determine if your problem is similar to what I experienced and could save diagnostic time.

My vehicle odometer reads 167712 KM and service records are up to date according to schedule. The vehicle antenna issue you described matches the symptoms I had. After reading through the responses, I got it checked and my problem was indeed related to the automotive antenna wiring. The technician found water damage causing signal interference with the vehicle antenna system. They replaced the cable connections and sealed the antenna mount properly. Total repair time was about 3 hours. The keyless features are now working perfectly again. The diagnostic scan showed no additional error codes after the repair.

Thanks for the update about your Q3s antenna repair, its always good to hear back about successful fixes. My Q5 had nearly identical symptoms when the antenna system failed around 165000 KM. The water damage to antenna wiring seems to be a common weak point in these models. After my repair, I asked the tech about prevention and learned that the fm antenna connections are especially vulnerable to moisture issues when the protective seals start degrading. Like in your case, once the radio signal pathway was restored with new wiring and proper sealing, all the keyless functions went back to normal. The repair cost was worth it considering how much we rely on these convenience features. One tip: Since having the repair done, I regularly check the bumper area seals during washing to catch any potential water intrusion early. This helps avoid future signal interference issues with the vehicle antenna system. Nice to hear your car is back to full functionality. The 3-hour repair time sounds about right based on my experience with the same fix.

Good to close this thread with confirmation about my Q3s repair. The automotive antenna issue turned out to be exactly what others suggested. My case adds to the evidence that water-damaged antenna wiring is a common problem around the 165000-170000 KM mark on these models. The repair process was straightforward: Diagnostic scan confirmed signal interference, Removed trim to access the antenna mount, Replaced damaged wiring to restore proper radio signal, Resealed the vehicle antenna connections, Final testing verified all keyless features Total repair time was 3 hours and everything works perfectly now. Going to follow the suggestion about checking seals during car washing to prevent future antenna system problems. Really appreciate all the helpful responses that pointed me in the right direction for this fix. For anyone searching later with similar symptoms, getting the antenna replacement done promptly is worth it to avoid more extensive electrical issues. The repair cost was reasonable considering the restored functionality.