Q3 Camshaft Sensor Symptoms Point to Urgent Repair Need

Had the same symptoms on my 2019 Q5 with the 2.0L TFSI engine. The check engine light and power issues pointed to a faulty camshaft position sensor, but it turned out to be a loose wiring connection at the sensor plug. The automotive sensor connections can deteriorate over time, causing intermittent engine misfire and timing issues. In my case, the mechanic first inspected the wiring harness and found corrosion at the connector pins. After cleaning the connections and securing the plug properly, the problems disappeared completely. This type of issue is generally straightforward for any qualified mechanic to diagnose with the right diagnostic tools. A competent shop should be able to differentiate between a failing sensor and a connection problem. The repair is not particularly complex, but proper diagnosis is crucial since similar symptoms can stem from various causes. The crankshaft and camshaft sensors work together, so problems with either can cause similar symptoms. Getting an accurate diagnosis is more important than the specific shop you choose, as long as they have experience with modern engine management systems.

Thanks for sharing your experience with the sensor connector issue. My 2021 Q3 had rough idling and stalling engine problems that sounded very similar. After getting a second opinion, it ended up being a combination of a failing camshaft sensor and dirty fuel injectors causing the engine misfire. Took about 2 days to fix everything. Would you mind sharing what the repair cost in your case? Just wondering how it compares, since I had to pay quite a bit at the dealer. Also, have you had any other sensor failure issues pop up since getting it fixed?

Thanks for asking about the costs. The repair for my Q3 was actually quite reasonable at 95 Euro, which covered diagnosing and fixing the faulty cable connection at the camshaft sensor. The stalling engine issues completely disappeared after the repair. Since having the automotive sensor connection fixed, the check engine light has stayed off and performance returned to normal. No other sensor problems have occurred in the past months. The key was getting a proper diagnosis, loose or corroded connections can mimic the symptoms of a completely failed sensor. This kind of repair should be straightforward for most shops since its typically just involving electrical connections rather than replacing the entire camshaft sensor unit. The crankshaft and other engine management sensors have all been working fine since the fix as well. Sounds like your case was more complex with the additional fuel injector work needed. A failing sensor combined with dirty injectors would definitely cause those idle and power issues you experienced.

Thanks for the advice. Just wanted to update on how it turned out. Took it to a different shop that specializes in engine diagnostics. They hooked up their scanner and found multiple timing issues related to the camshaft sensor. The rough idling turned out to be from a damaged wiring harness that was causing intermittent engine misfire problems. The total repair came to 280 Euro including parts and labor. They replaced the damaged wiring, installed a new camshaft sensor, and cleaned the connections. The engine runs perfectly now, no more hard starts or power loss issues. Much better experience than my previous mechanic who just wanted to replace parts without proper diagnosis. The new shop took time to properly trace the wiring and test all the automotive sensors before making repairs. Really glad I got that second opinion instead of continuing with the first place.