Audi A4 Dash & Turn Signal Glitches Need Quick Fix

Had the same issue on my 2020 Audi A5 with the 2.0 TFSI engine. The problem turned out to be more than just a basic bulb replacement. The main fault was traced to corroded connector pins in the main wiring harness that feeds the turn signal and automotive lighting system. The indicator light problems were actually a symptom of a larger electrical connection issue. The speedometer errors appeared because the same wiring harness connects to multiple systems through the vehicle control modules. The repair involved removing the front bumper to access the main connector block, cleaning all connection points, and replacing several damaged pins. While not a catastrophic repair, it was definitely beyond simple lamp replacement or flasher relay issues. The warning signs were similar: inconsistent turn signal operation followed by dashboard errors. The automotive lighting system showed intermittent faults, particularly affecting the passenger side indicator light. Worth having the wiring harness connections checked, especially around the headlight assemblies where water can sometimes collect and cause corrosion.

Thanks for that detailed write-up about the wiring harness issue. Just curious, do you remember what the final repair cost came to? I am seeing more electrical fault codes now in my A4, and the turn indicator started acting up again this morning. Wondering if I should budget for a similar repair. Also, has everything worked perfectly since the fix, or have you noticed any other electrical gremlins popping up?

Happy to report that after visiting the mechanic last week, the indicator light issues have been completely resolved. The repair was much simpler than the wiring harness problem I initially described. The electrical fault turned out to be a loose cable connection to the turn signal lamp assembly. Total cost came to 95 Euro for diagnosing and fixing the faulty connection. Much less expensive than I originally anticipated when dealing with automotive lighting problems. Since the repair, all signal lamps are working flawlessly with no more dashboard warnings or electrical gremlins. The turn indicator now functions properly on both sides, and the speedometer errors have disappeared completely. It shows that sometimes what appears to be a complex electrical fault can have a straightforward solution. This experience was much more positive than the previous repair work I mentioned. If your symptoms are similar, it might be worth having the connections checked first before assuming worst-case scenarios with the entire wiring system.

The mechanic visit turned out better than expected! After seeing those worrying electrical faults and problematic turn signals, I was preparing for the worst. But the fix was surprisingly straightforward and affordable. The mechanic found a loose connection in the turn signal assembly that was causing all the trouble. Just a quick cable reconnection and proper securing of the automotive lighting components solved both the indicator light issues and those annoying dashboard errors. Total repair came to 95 Euro, way less than I feared when thinking about potential wiring harness problems. The broken lens assembly I was worried about turned out to be fine, and no flasher relay replacement was needed. My A4 has been running perfectly for the past week, no more electrical gremlins, no dashboard warnings, and all lights working as they should. Really glad I got this sorted quickly before it could develop into something more serious.