VW Up Key Fob Issues, Quick Fixes and Warning Signs

As someone with moderate car repair experience, I had a very similar issue with my VW Polo 2016. The auto key started acting up with the same symptoms, unreliable central locking and keyless entry failures. The car kept showing low battery warnings for the key fob. I initially worried it might be something major, but it turned out the key battery was simply dead. Had it fixed at a workshop that specializes in auto electronics, total cost was 37€ including the new battery and programming check. For key battery replacement, they used a CR2032 battery which solved all issues immediately. The warning messages disappeared and all key functions worked perfectly again. To better assist with your specific case, could you share: Does the physical key part still work for manual door unlocking? When did the warning messages first appear? Have you noticed the issue getting worse over time? Are you having any other electrical issues with the car? This is typically a straightforward fix, but knowing these details would help confirm if your symptoms match what I experienced with my Polo.

Just had my 130000km service last week. The physical key still works fine for manual unlocking. The low voltage warnings started about 2 weeks ago and got worse quickly. The fob battery seems to be the culprit since all other electrical systems work perfectly. After reading up on similar cases in the forums, it seems quite common for car key fobs to need battery replacement around the 4-5 year mark. Going to try replacing the battery first before considering more expensive repairs. No other electrical problems, starter, lights, and all electronics working normally. Just this annoying key fob issue making the keyless access unreliable.

Thanks for those details. Your case sounds exactly like what I experienced with my Polo. When my electronic key started acting up after about 4 years, it followed the same pattern, first occasional glitches, then rapid deterioration of the key fob functions within weeks. The 4-5 year battery life matches my experience perfectly. Since your physical key works and other systems are fine, a dead key battery is almost certainly the issue. These symptoms are textbook for low battery in the key fob, especially the gradual loss of keyless access followed by complete failure. The service history and mileage you mentioned actually help confirm this, my issues started right around the same usage period. A fresh CR2032 battery should restore full functionality. The whole fix cost under 40€ at the workshop, including programming verification. The key fob battery replacement resolved all problems: Keyless access worked properly again, Warning messages disappeared, Normal locking range was restored, Remote functions became reliable Given how similar your symptoms are, I would definitely try the battery replacement before exploring more complex solutions.

Thanks for the helpful responses. I really appreciate the detailed feedback about key fob battery issues and replacement costs. Just wanted to update that I got the electronic key battery replaced today. Used a CR2032 battery as suggested and the fix cost 35€ including a quick system check. The keyless access is working perfectly again and all warning messages have cleared from the dashboard. Really glad it turned out to be just a low battery situation rather than anything more serious. The remote locking range is back to normal and everything functions like new. Will definitely keep in mind the 4-5 year battery life cycle for future reference. Makes sense to try the simple battery replacement first before worrying about bigger issues. The symptoms matched exactly what others described with their key fob battery problems. Sharing this experience in case anyone else runs into similar electronic key troubles down the road.