Audi SQ5 Keyless Entry System Complete Failure Fix

Dealt with a very similar door electronics issue on my 2015 S4 last year. Have some experience working on basic car repairs but left this one to the professionals since it involved the locking system. The symptoms match exactly what you described, complete failure of the keyless entry and door handle electronics. After initial diagnosis, it turned out to be a wiring fault where a cable connection had worked loose inside the door mechanism. The workshop found the specific door electronics plug that was causing the issue during testing. The repair cost me 95 Euro including diagnostics and fixing the connection. Much better than replacing the entire door handle assembly which was my initial worry. Would be helpful to know: Have you noticed any intermittent issues before the complete failure? Does this happen on all doors or just one specific door? Are there any other electrical issues showing up? If you can share these details, it would help determine if your issue matches the wiring fault I experienced. The workshop mentioned these door electronics problems are fairly common on this platform, often caused by loose connections rather than complete component failure.

Just had my latest service done at 127200 KM where they updated the control modules, so I can add some details to this discussion. My experience started exactly the same way, the door handle stopped responding out of nowhere. In my case, a faulty connection in the wiring was causing the electric door system to malfunction. The sensor issue was triggered by moisture getting into a poorly sealed wire connector. Turned out the door actuator itself was perfectly fine, saving quite a bit on parts. The workshop traced the wiring fault to a specific harness connection. Total repair came to 220 Euro including full diagnostics and weatherproofing the connection point. Definitely get the error code read first, it will narrow down whether its truly the door electronics or just a connection problem like mine was.

The wiring fault diagnosis matches what I experienced on my S4 as well. After going through a similar repair with my door handle electronics, I learned these connection issues often start with moisture intrusion, just like your case. Since you mentioned the control module updates, were there any communication faults stored before the update? With my repair, the technician found multiple stored codes related to the door electronics that cleared up once they fixed and properly sealed the connector. The 220 Euro repair cost seems reasonable considering they did the weatherproofing. My initial 95 Euro fix needed a follow-up visit because they didnt properly seal the door mechanism connections the first time around. The proper weatherproofing you got done should prevent future moisture-related electric door failures. For anyone else reading this thread, if your keyless system starts acting intermittently, check for error codes immediately. Early diagnosis of door electronics issues can prevent more extensive damage to the system.

As the original poster, I really appreciate all the feedback and sharing of experiences. The door handle issue does seem to follow a common pattern with these models, and the wiring fault diagnosis matches my symptoms exactly. Just to close the loop on my original questions about repair costs and workshop experiences, the 220 Euro fix including diagnostics and weatherproofing turned out to be very reasonable. The key learning was that door electronics failures often trace back to moisture-affected wiring rather than complete door mechanism failure. For others searching the forums with similar keyless entry problems, definitely get those error codes pulled first. The door switch issues can seem daunting, but often the fix is much simpler than replacing entire door handle assemblies. In my case, identifying the specific wiring fault early prevented more expensive repairs down the line. The workshop did solid work sealing up the connections properly, and the keyless system has been working flawlessly since the repair. Much better outcome than initially feared when the door electronics first failed.