Audi S3 Key Fob Problems: Beyond the Battery Fix

I had the exact same issue with my 2008 S4 last month. As someone who does basic maintenance but leaves electronics to the pros, this turned out simpler than expected. Started with the same symptoms, dead key fob that wouldnt unlock doors or start the car. The electronic key showed the low battery warning, just like yours. First, tried a DIY fix watching tutorials, but wasnt confident opening the key fob myself. Took it to a workshop where they diagnosed a completely drained battery in the key. The fix was straightforward, they replaced the fob battery and cleared the error codes. Total cost was 37 Euro including labor. Before suggesting specific solutions for your case, could you share: Have you noticed the key fob getting weaker gradually or did it stop suddenly? Are you able to start the car using the physical key? Does the key fob feel loose or make rattling sounds? The workshop mentioned these auto key issues are quite common in models from that era, but its worth checking these details to rule out other potential problems beyond a simple dead key battery.

Thanks for the feedback. Just to confirm, mine started failing gradually over about 2 weeks before completely dying. The physical key still works fine, and the fob itself feels solid with no rattling. My last service was at 188527 KM and they did not flag any potential key fob issues during the inspection. Since the low voltage warning appeared on the dash, it sounds like a straightforward fob battery replacement should resolve it. Going to try that first before looking into more complex key programming issues. Did your shop mention how often the key battery typically needs replacing? Want to stay ahead of this in the future rather than getting caught off guard again.

Based on my experience with the exact same car, key fob batteries usually need replacing every 3-4 years. When I had mine serviced, the technician explained that electronic key systems from this era start showing low voltage warnings well before complete failure, which gives a good window to act. The gradual decline you described matches my situation perfectly. The warning signs appeared over a couple weeks before total failure, classic symptom of a depleting fob battery rather than a programming issue. Since your physical key works and there is no damage to the fob housing, I am even more confident its just the battery. After my battery replacement, the shop advised setting a reminder for future key battery checks around the 3-year mark. They mentioned that extreme temperatures can affect battery life, so usage conditions can shift this timeline. One tip: make sure to get the correct battery type for the fob. Using an incorrect or low-quality replacement battery can trigger false error codes. The battery replacement itself is quite affordable, mine was under 40 Euro including clearing the stored error codes.

Thanks everyone for the helpful information. Given all the feedback and similarities to other cases, I feel confident moving forward with the fob battery replacement as the first step. The gradual failure pattern of my key matches the typical low voltage symptoms, and it's reassuring to hear this is a common maintenance item. Will schedule the battery swap this week and make sure they clear any stored error codes while they're at it. The 40 Euro price point seems reasonable for the service. Really helpful to know about the 3-4 year replacement interval too, definitely adding that to my maintenance schedule to avoid getting stranded with a dead key again. Going to ask the shop to confirm the correct battery type during the replacement. Once it's fixed, I'll keep monitoring for any lingering electronic key issues, but sounds like a fresh fob battery should get everything working normally again.