Multiple Warning Lights Point to Audi SQ5 Oil Sensor Issue

Had a similar issue with my S4 (2016) about a year ago, speaking as someone with some hands-on experience maintaining performance cars. The oil temperature sensor warning started appearing along with multiple other warning lights, pretty much identical to what you are describing. After some basic checks, I had my workshop inspect it. They found that the connection between the oil sensor and its wiring harness was compromised. The engine sensor wiring had some corrosion at the plug, causing intermittent signals. The fix was straightforward, they cleaned the connections and replaced a damaged plug. Total cost was 95 Euro including diagnostic time. All warning lights cleared after the repair and have not returned since. Before jumping to conclusions though, would you mind sharing: Current mileage on your SQ5? Are you noticing any performance issues? When did these warning lights first appear, all at once or gradually? Have you recently had any oil changes or other maintenance work done? This information would help determine if your automotive sensor issue matches what I experienced or if it might be something different. The oil temperature and pressure systems are pretty interconnected, so getting an accurate diagnosis is important.

Just had my last service at 149680 KM. No performance issues noticed before the warnings appeared. They all came on suddenly during a regular drive. The engine temperature and oil gauge readings were fluctuating before the warnings started. I got it checked at a workshop and their car diagnostics showed P0196 error code, pointing to the temp sensor. Replaced the wiring first but the issue persisted. Would be helpful to know if anyone else needed the full sensor replacement or if there are other fixes to try first.

Thanks for providing those details. When I had similar symptoms with my S4, I first tried the wiring fix like you did, but ultimately needed to replace the entire temperature sensor unit. The fluctuating gauge readings you mentioned are exactly what I experienced before the full sensor failure. The P0196 code with unstable temperature and oil gauge readings strongly suggests the sensor itself is faulty, not just the connections. The automotive sensor in these engines is known to occasionally fail around the 150000 km mark, which aligns with your mileage. The full sensor replacement on my car cost about 280 Euro including labor. Since then, all readings have been stable and warning lights cleared completely. The car diagnostics confirmed the fix was successful. One tip from my experience: make sure the workshop uses the correct specification temperature sensor, as there are several variants. An incorrect sensor can cause similar symptoms even when new. Would recommend getting the sensor replaced soon, as inaccurate temperature readings could mask potential engine issues. While the car runs fine now, accurate monitoring of engine oil temperature is crucial for these engines.

Based on the conversation, here is how I would respond as the original poster: Thanks for sharing your experience, sounds exactly like what Im dealing with. My readings match yours, and the fact that it happened around the same mileage point is telling. I appreciate the tip about sensor specifications, as I definitely want to avoid installing the wrong part. The complete sensor replacement cost seems reasonable considering the alternative of continuing to chase intermittent issues. Since my car diagnostics already confirmed the P0196 code and the engine sensor is showing the same symptoms you described, I will go ahead and schedule the full temperature sensor replacement. Better to address it now while its just a sensor issue rather than risk any engine damage from incorrect temperature readings. Will update once the repair is done in case it helps others troubleshooting similar automotive sensor problems.