Audi Q3 Multiple Electrical Faults Baffle Owners

I had a very similar issue with my 2020 Audi Q5 2.0T last year. Having some experience with electrical issues on modern cars, I recognized these symptoms immediately. The warning signals started appearing out of nowhere, check engine light flickering, infotainment glitches, and various warning lights on the dash. Engine diagnostics showed multiple error codes that kept changing. The service required message would pop up intermittently. After attempting basic troubleshooting like checking battery connections and fuses, I took it to a workshop. They diagnosed a faulty cable connection to the main control unit that was causing communication issues across the BUS system. The intermittent nature of the problem made it challenging to diagnose initially, but they used specialized diagnostic equipment to trace the connection faults. The repair cost me 155 Euro, which included diagnostic time and replacing the defective connection. Since the fix, all systems have been working perfectly with no warning lights or glitches. Could you share more details about your Q3: When did these issues first start? Does it happen more frequently when the engine is cold or warm? Have you noticed any pattern with the warning light activation? Did you have any recent work done on the electrical system? This information would help determine if your issue is similar to what I experienced.

Thanks for sharing your experience. My issues started about 2 weeks ago at 126282 KM. The last service was completed just 3 months ago with no issues reported. The warning light pattern seems completely unusual, occurring in both cold and warm conditions. The check engine light usually triggers first, followed by system failure messages on the dash. I have not had any recent electrical work done. One thing I noticed is that cycling the ignition sometimes temporarily clears the warning signals, but they return within a few minutes of driving. I will definitely have the control unit connections checked based on your experience. Has anyone else faced similar electrical gremlins with such unpredictable behavior? Knowing the scan tool shows different codes each time makes me suspect a wiring issue rather than individual component failures.

Great that youre seeking more details. After fixing my Q5s connection issue, I learned a lot about these electrical gremlins. The behavior you describe with cycling the ignition temporarily clearing the warning signals matches exactly what I experienced. This is typically a telltale sign of communication problems between control modules rather than actual component failures. When my issues occurred, the scan tool would show different trouble codes each time, ranging from transmission control module errors to unusual check engine warnings. The workshop explained this happens because when the main control unit loses communication, other systems report faults due to missing data. Something important I discovered: temperature changes and vibration while driving can make loose connections worse, which explains the unusual timing of the warning signals. In my case, the connection would deteriorate gradually during each drive. The workshop used advanced engine diagnostics to monitor the communication signals in real-time, which helped identify the exact location of the failing connection. Given your symptoms are nearly identical, I strongly suspect youre dealing with the same root cause. Consider requesting a thorough check of all control module connections, especially around the main harness. The diagnostic time might cost extra, but its worth avoiding replacing parts unnecessarily.

Thanks everyone for the helpful responses. I scheduled a workshop appointment for next week and will specifically request they check all control module connections and wiring harnesses. The part about temperature changes and vibrations affecting connections makes perfect sense, as I notice more system failure warnings after driving on rough roads. The workshop confirmed they have advanced engine diagnostics equipment to trace intermittent communication issues. Will update once they complete the diagnosis and repairs. The scan tool readings continue showing unusual codes, but at least I now have a better understanding of why this happens when control modules lose communication. Most importantly, knowing that others resolved similar electrical gremlins without major component replacement gives me hope this will be a straightforward fix rather than an expensive repair involving multiple parts. Let me know if anyone else experienced these symptoms and found different root causes. The more information we share about these intermittent electrical issues, the better equipped we all are when facing similar problems.