Audi Q2 Sensor Issue: Stalling & Start Problems

Having some experience with diesel engines, I encountered a very similar issue with my 2021 Audi Q3 diesel last year. The symptoms matched yours exactly, engine misfire, difficult starting, and persistent check engine light. Initially, I suspected the crankshaft sensor, but after diagnostic testing, the workshop identified a defective encoder wheel on the camshafts as the root cause. The engine control system was receiving incorrect timing signals, leading to the stalling and starting issues. The repair involved replacing both the encoder wheel and associated sensors. Total cost was 695 Euro, including parts and labor. The fix completely resolved all symptoms, and the engine has run perfectly since. Before suggesting this is definitely your issue, could you provide: Current mileage, Whether you notice any specific patterns when the stalling occurs, Any diagnostic codes retrieved from the engine control unit, If there are any unusual sounds during startup This information would help confirm if your Q2 is experiencing the same problem my Q3 had. The symptoms you describe are serious enough to warrant immediate attention, as continued operation could potentially cause additional engine damage.

Latest service was done at 77564 KM, which is when the technician first noticed occasional misfires during the diagnostic scan. The ignition timing issue seems to be getting worse, especially during cold starts. After running the sensor testing procedures, the results show intermittent signal disruption from the camshaft position sensor, which aligns with the engine misfire patterns others have mentioned. I would appreciate if someone could confirm whether these symptoms typically indicate a failing sensor unit or if there might be wiring issues to check first. Getting quotes from several shops, but prices vary significantly from 450 Euro to 850 Euro for the complete repair.

Thanks for the additional details about your Q2. After dealing with similar issues on my Q3, I can definitely relate to your concerns about the varying repair quotes. Having gone through the repair process, I strongly recommend checking the wiring harness first. While my camshaft position sensor did turn out to be faulty, the initial diagnosis revealed corroded wiring connectors that were contributing to the intermittent signal issues. The check engine light patterns and cold start problems you describe match exactly what I experienced. The crankshaft sensor readings should also be verified since it works in conjunction with the camshaft sensor to maintain proper engine timing. In my case, the engine control module was receiving conflicting signals from both sensors due to the wiring corrosion. Based on your mileage and symptoms, this definitely sounds like more than just a wiring issue. My repair bill of 695 Euro included: New camshaft position sensor, Wiring harness repair, System diagnostic and calibration The shops quoting 850 Euro might be including preventive replacement of the crankshaft sensor, which could be worthwhile given the mileage. The 450 Euro quote seems low and might not include necessary recalibration work.

I appreciate the detailed feedback about the sensor and wiring issues. Based on my car's symptoms and your repair experience, it seems the higher repair quotes might actually be more realistic, considering the comprehensive work needed. The cold start problems and engine misfire patterns have become more frequent this week. Yesterday morning, the check engine light started flashing during my commute, and the car stalled twice at traffic lights. These symptoms match exactly what you described with your sensor and wiring harness issues. Given the risk of additional engine damage, I will schedule the repair next week. Will opt for the 795 Euro quote that includes both camshaft position sensor replacement and complete wiring harness inspection. Their diagnostic report also mentioned checking the crankshaft sensor as a preventive measure, which makes sense considering the mileage. Thanks for helping me understand the scope of repairs needed. Having someone share a similar experience really helped confirm my suspicions about the sensor being the root cause.