Audi S8 Trans Warning: Grinding Shifts and Limp Mode

Just dealt with remarkably similar transmission issues on my 2004 A8, which shares many components with your S8. Having some experience with transmission problems, I can relate to these symptoms. The grinding sounds and rough shifting matches exactly what I experienced. My transmission pressure gauge was showing inconsistent readings, which turned out to be caused by low transmission fluid level rather than a faulty pressure sensor or transmission sensor. After visiting my regular workshop, they performed a thorough diagnostic. The pressure switch readings were normal, but the oil level was significantly below minimum. The fix involved: 1. Complete transmission fluid level check 2. System inspection for potential leaks 3. Fluid top-up and adjustment 4. Reset of transmission control module Total cost was 365 Euro including diagnostics and fresh fluid. The symptoms disappeared completely after the service. Before suggesting more specific solutions, could you share: Current mileage? When was the last transmission fluid change? Are there any visible fluid leaks under the car? Does the problem get worse when the transmission is hot? This information would help determine if you are facing the same root cause or if there might be other issues at play.

Had my last service at 63000km, only about 800km ago. After the diagnostic scan, it turned out the transmission fault was indeed linked to the oil pressure sensor giving erratic readings. The sensor was replaced under warranty since my last maintenance package was still active. No fluid leaks were found during inspection, and the oil level checked out fine. The transmission now shifts smoothly with no warning lights. Worth checking your sensor connections and readings if anyone encounters similar symptoms with rough shifting and warning lights.

Thanks for the follow-up on your S8 transmission issue. The symptoms on my A8 were indeed very similar, though my case had a different root cause. Your experience with the faulty oil pressure sensor is particularly interesting, as this matches another case I dealt with last year. While my initial problem was solved through fluid level correction, the transmission fault returned about 6 months later. The second time, it was actually the pressure switch giving false readings despite normal oil levels. The repair process involved: 1. Diagnostic scan confirming erratic pressure sensor signals 2. Complete oil sensor replacement 3. Transmission control module reset Cost was 280 Euro for parts and labor, but yours being covered under warranty is even better. The repair has held up perfectly since then with no transmission fault codes or warning lights. This reinforces that similar symptoms can have different causes, from simple oil level issues to sensor malfunctions. Getting a proper diagnostic scan is crucial rather than just assuming and replacing parts.

Glad I could share my experience and help others who might face similar transmission issues. The warranty coverage was definitely a relief, considering these sensor replacements can be costly. My transmission sensor problem could have easily been misdiagnosed as something more serious, which shows the importance of proper diagnostics. The oil pressure readings are now stable, and the transmission works perfectly after the sensor replacement. For anyone searching the forum later with similar transmission issues and warning lights, definitely get the oil pressure sensor checked before assuming worst-case scenarios. The repair was straightforward once correctly diagnosed, and I havent seen any transmission fault codes since. Regular maintenance and monitoring transmission oil pressure can help catch these problems early. Just logged another 2000km with zero issues, smooth shifting, and no warning lights. Sometimes the simplest solution, like a faulty sensor, is the correct one, even when the symptoms seem severe.