Q3 ABS Light + Brake Issues: Speed Sensor Alert

Had similar issues with my 2019 Audi A4 2.0T. The ABS and stability control malfunction started the same way, multiple warning lights on the dashboard. Initial diagnostic revealed it wasnt just a speed sensor, but the ECM had communications issues with the ABS module. The repair required replacing the ABS control unit since it was defective. This is a serious issue that affects vehicle safety systems. The problem gets worse if left unattended, as the stability control and brake assist functions become unreliable. The repair process involved: Full system diagnostic scan, Testing communication between modules, Replacing the ABS control unit, Programming and coding the new unit, Testing all safety systems After fixing it, all systems worked normally again, proper brake function, stable handling, and no more warning lights. Given the safety implications, recommend having it checked by an Audi specialist who can properly diagnose the ECM and ABS module communication. This isnt a quick fix job, the control unit replacement requires specific programming equipment and expertise with VAG systems.

Thanks for sharing your experience. Had almost the exact same issue on my Q3 last year, the ABS malfunction, multiple warning lights and brake instability were pretty scary. Good to hear replacing the ABS control unit sorted it out completely. Would you mind sharing how much you ended up paying for the full repair? My sensor and ECM issues cost around 1200 Euro in total, but wondering if prices vary much. Has everything stayed working properly since the fix? No dashboard warnings or other electronic glitches popping up?

Thanks for asking about the follow-up. The speedometer and ABS systems have worked flawlessly since getting the repair done. The ECM communication issues and sensor malfunction were completely resolved after replacing the faulty control unit. Total cost came to 1000 Euro, which covered the diagnostic work, new unit, and programming. This seems in line with what you paid for your repair. The price typically depends on parts availability and programming time needed. No warning lights or electronic glitches have appeared in the 8 months since the fix. The stability control and brake assist functions are working exactly as they should. The input from all sensors is being properly processed by the control unit now. Getting it fixed by a qualified shop that could properly diagnose and repair the ECM communication issues was definitely worth the investment, considering these are critical safety systems.

I finally got my car back from the mechanic last week. The repair process went much smoother than my previous attempts at fixing the ABS malfunction. The diagnostic test confirmed issues with both the speed sensor and ECM communications. The total repair came to 1150 Euro, covering: Full system diagnostic scan, New ABS control unit, ECM reprogramming, Labor costs After a week of driving, the transmission and brake systems work perfectly. No more warning lights or stability control issues. The car feels solid during braking, and the traction control works as intended. Much better experience than my last mechanic who just kept replacing unusual parts without fixing the root cause. The shop took time to explain the diagnostic results and why the control unit needed replacement. Worth every cent to have these safety systems working properly again. Really glad to have this sorted before winter driving conditions.