Q5 Fuel Door Lock Failure: Actuator Issues Spreading

Had the same issue on my 2015 Audi A4 2.0T. The fuel flap release button stopped responding completely, similar to your symptoms. The lock actuator had failed, which also affected the central locking system. The issue requires removing the entire fuel filler assembly to access the mechanism. Main culprits are usually either a broken linkage between the release button and actuator, or a failed lock actuator itself. In my case, both components needed replacement since the linkage was damaged from forcing the mechanism. This is a moderately serious repair that requires specific expertise with fuel system components. The job involves carefully disconnecting the fuel filler neck and dealing with multiple electrical connections. Not recommended as a DIY fix due to fuel system safety requirements. The key fob functions may also be affected when the lock actuator starts failing, which matches your symptoms. Would recommend having it diagnosed at an Audi specialist rather than a general repair shop, as they will have the proper diagnostic equipment to confirm the exact failure point.

Thanks for sharing your experience. The same thing happened to me, the fuel flap release mechanism completely failed on my Q5. After diagnosis, it turned out the cable release had snapped and the electrical fault in the actuator caused the central locking issues. Wondering how much you ended up paying for the repair and if any other related problems came up afterwards? Would help to know since I had a few electrical gremlins pop up months later that might have been connected to this issue.

Finally got the repair done last week. The electric actuator and cable release system were both replaced since the original linkage was completely defective. Total cost came to 210 Euro which included parts and labor. The fuel door now works perfectly with both the interior button and key fob. No electrical issues since the repair. The lock actuator replacement seemed to fix all the related problems with the central locking system too. The fuel filler mechanism is operating smoothly now, much better than before when it was sticking and causing frustration. Worth mentioning that having a proper diagnosis first saved time and money. The mechanic quickly identified the broken components in the fuel door mechanism rather than replacing parts unnecessarily. The repair has held up well so far. If you notice any electrical quirks, have them checked right away while everything is still fresh in the mechanics mind.

I took my Q5 to a certified shop last week after reading your helpful replies. The mechanic confirmed the electrical fault was indeed caused by a failed lock actuator, just as you described. The release mechanism had completely seized up. The repair took about 3 hours total. They replaced both the electric actuator and the cable assembly since the original release mechanism was beyond repair. Total bill came to 275 Euro, bit more than expected but worth it to have it done properly. Happy to report the fuel filler door now works perfectly with both the interior button and key fob. No more fighting with the flap or worrying about getting stranded at gas stations. The central locking is also back to normal, which was an unexpected bonus. Definitely the right call to get it fixed at a specialist shop rather than attempting any DIY solutions. The fuel system components needed special handling and proper diagnostic equipment to get everything working correctly again.