Audi RS3 Central Lock System Complete Failure Fix

Having some experience with car electronics, I dealt with a very similar issue on my 2015 Audi S3. The keyless entry system completely stopped working, leaving me with the same symptoms, no response from the key fob and non-functioning door locks. After taking it to a workshop, they found the main culprit was a faulty wiring harness connection near the car alarm control module. The pins in one of the connectors had corroded, breaking the circuit for the entire central locking system. The repair involved cleaning the connector and replacing a damaged section of the wiring, costing 95 Euro including diagnostic time. Before going to the workshop, make sure to check your fuse box, specifically the fuses related to the central locking system and car alarm. A blown fuse could cause these symptoms, though in my case it turned out to be the wiring issue. To provide more specific guidance for your RS3, could you share: Have you noticed any other electrical issues recently? Does the manual key still work in the driver door lock? Are there any other warning lights on the dashboard? Did this issue start suddenly or gradually?

Thanks for your detailed insights. My car has 44816 KM and its central locking started failing suddenly after a rainy weekend. The manual key still works fine in the driver door, but the remote locking functions are completely dead. No other electrical issues noticed and dash displays normally. I checked all fuses according to the manual but found none blown. The security system remains unresponsive regardless of weather conditions. I noticed the door locks make no sound at all when attempting to use the remote, which seems to point toward a complete system failure rather than just a fob issue. Has anyone else found the repair cost exceeded 500 Euro for a similar locking mechanism problem?

Based on your description, this sounds remarkably similar to what I experienced with my S3. The symptoms after rain exposure match exactly what happened with my central locking system. The fact that your manual key works but the electronic functions are completely dead strongly suggests a water-related electrical issue. In my case, after the initial wiring harness repair I mentioned, the problem actually returned a few months later. The second diagnosis revealed water had seeped into the door lock actuator, causing corrosion in the connector. The total repair ended up being more expensive than expected, around 680 Euro including parts and labor, as they had to replace the entire door lock mechanism. A key indicator that points to water damage is the complete silence from the door locks when using the key fob. When the actuators are working properly, you should hear a distinct sound. The absence of this sound, combined with your car being exposed to rain before the failure, makes me think you might be dealing with the same water intrusion issue I faced. If you want to avoid potentially higher repair costs later, I would recommend having the door seals checked and the drain holes cleared during the repair. This helps prevent future water-related failures in the car locks and electrical systems.

Thanks for the advice. After hearing about the water damage possibilities, I took it to my mechanic today. Turns out water had indeed gotten into the driver side door lock actuator, damaging both the mechanism and surrounding wiring. The full repair quote is 890 Euro including a new door lock assembly, wiring repairs, and complete system diagnostic. They also found the drain holes were partially blocked, which explains the water buildup. Going to have them clear all drainage channels while they're at it to prevent future issues with the security system. Just glad the key fob itself wasnt the problem, as I heard those can cost even more to replace. The car is currently in the shop and they say parts will arrive in a few days. Will update once everything is fixed in case anyone else runs into similar door locks problems with their RS3. Main lesson learned is to regularly check and clean those drain holes!