Audi A3 Camshaft Sensor Issues: Fix Guide & Symptoms

I had a very similar issue with my 2002 Audi A4 petrol last summer. Having some experience with basic car maintenance, I initially thought it was just a timing issue, but the check engine light and poor starting symptoms pointed to something more serious. The engine misfire and power loss matched your symptoms exactly. After scanning, it also showed camshaft position sensor-related codes. When I took it to my workshop, they found the problem was actually a loose connection at the sensor plug rather than a faulty sensor itself. The repair was relatively straightforward, they cleaned the contacts and properly secured the cable connection. Including diagnostics, the total cost was 95 Euro. The engine has been running perfectly since then, with no more starting problems or power issues. Before suggesting specific fixes for your A3, it would help to know: What exact fault code are you getting? Does the check engine light stay on constantly or flicker? Have you noticed any sensor failure warnings on the dashboard? Is the poor running worse when the engine is cold or hot? This additional information would help determine if your issue is similar to what I experienced with the wiring, or if you might be dealing with a different problem.

Thanks for the helpful response. My fault code is P0340 and the check engine light stays on constantly. The latest service was done at 180000 KM, mainly just an oil change and standard checks. The automotive sensor issues are definitely worse when the engine is cold, particularly during morning starts. I have not seen any specific sensor failure warnings on the dash besides the check engine light. The crankshaft seems to turn over normally during starting, but the engine takes much longer to catch compared to before. The loose connection you mentioned is an interesting point, I will check the camshaft position sensor wiring before replacing any parts. A 95 Euro fix would be much better than a full sensor replacement.

Thanks for providing those details about your A3. The P0340 code and cold-start issues match exactly what I initially experienced with my A4. While my issue was resolved with the wiring fix, I should mention that after helping another club member with the same symptoms, we discovered his problems stemmed from a completely failed camshaft position sensor. Since you are experiencing worse performance during cold starts, and the engine takes longer to catch despite normal crankshaft operation, this strongly suggests either a wiring issue or a failing sensor. Timing issues often start intermittently before becoming constant problems. The fact your engine misfire symptoms are more pronounced during cold starts actually helped me rule out several other potential causes in my case. If you plan to check the wiring yourself, look specifically for: Corroded or loose pins in the sensor connector, Wiring harness damage near the sensor mount, Buildup of oil or debris around the sensor area If cleaning the connections and securing the wiring does not resolve the stalling engine behavior, a new sensor will likely be needed. The part typically costs around 85 Euro plus labor if you need a shop to handle the installation. Let us know what you find when checking the wiring. Based on the matching symptoms and fault code, I suspect you will find either damaged wires or evidence of sensor degradation.

Thanks to everyone who replied. I wanted to provide an update on my A3 situation. After inspecting the wiring as suggested, I found significant oil contamination around the sensor connector. The pins were also quite corroded. I cleaned everything thoroughly and reconnected it, but the engine misfire symptoms persisted. I ended up replacing the camshaft position sensor since the wiring fix alone didn't solve the stalling engine problem. The part cost exactly what was mentioned, 85 Euro. I decided to do the installation myself after watching some repair videos. The whole job took about an hour. The timing issues and cold start problems are now completely resolved. The check engine light has stayed off, and the engine runs with full power again. No more sensor failure codes in the diagnostic readings either. For anyone else facing similar symptoms, I recommend checking the wiring first but be prepared that the sensor itself might need replacement. The total cost was still much lower than I initially feared, and the improvement in performance was immediate.