Audi S4 Trans Warning: Sensor vs Gearbox Failure Alert

Had similar transmission issues with my 2005 Audi S6. The symptoms match what you describe, rough gear shifting and grinding noises during acceleration. The transmission warning and limp mode are typical indicators of low transmission fluid or a faulty gearbox sensor. In my case, the transmission temperature sensor failed, causing incorrect readings and protective limp mode activation. The repair involved replacing both the sensor and the gearbox oil, as metal particles were found during inspection. The old sensor was completely corroded, likely due to heat exposure and normal wear. This is a serious issue that requires proper diagnosis. Running the transmission with incorrect temperature readings can cause permanent damage to internal components. The grinding sounds suggest possible internal wear already occurring. The temperature sensor is a common failure point on these transmissions. While sensor replacement alone might fix the issue, a full transmission fluid change is recommended to prevent future overheating problems. Make sure they check for metal particles in the old fluid, this indicates if internal damage has occurred. Would strongly advise against driving the car until properly diagnosed, as continued operation could lead to complete transmission failure.

Thanks for sharing your experience. The symptoms match what Im experiencing with my S4. Its good to know that changing the transmission temperature sensor plus fluid resolved your issue. Really hoping my automatic transmission wont need a complete overhaul. The transmission repair costs can get out of hand quickly. Might just give the sensor replacement a try first since that seems to be the common issue. Do you remember roughly how much you paid for the sensor and transmission oil change? Also, has everything been working fine since the repair or did you notice any other problems?

Good news, had my transmission issues completely resolved after taking it to a mechanic. The faulty transmission oil temperature sensor was indeed the culprit, just as suspected. The total repair came to 365 Euro, which included fixing the low gearbox oil level that was discovered during inspection. The automatic transmission has been working flawlessly since the fix, no more grinding noises or rough shifts. The warning lights cleared up immediately after the sensor replacement. Its been about 6 months now with zero overheating problems or transmission-related issues. The mechanic mentioned these temperature sensors commonly fail on these models, leading to incorrect readings and transmission protection mode. Getting it fixed early likely prevented more serious internal damage to the gearbox. If your symptoms match mine, addressing the sensor issue sooner rather than later could save you from costly transmission repairs down the line. The investment was definitely worth avoiding potential major transmission failure.

I decided to take it to a certified transmission repair specialist based on your feedback. Turns out you were spot on, it was the transmission temperature sensor causing all the trouble. The mechanic found the sensor completely shot and the transmission oil was a bit low. Total bill came to 390 Euro for the sensor replacement and transmission oil top-up. Way better than I expected, especially considering my last mechanic wanted to rebuild the entire gearbox. The automatic transmission is shifting smoothly now, no more grinding or warning lights. Really glad I caught this early before any serious damage occurred. The mechanic showed me the old sensor, it was totally corroded, just like you described. The whole repair took about 3 hours. Definitely worth finding a specialist who knew exactly what to look for instead of going back to my regular guy. Thanks for helping me avoid an unnecessary expensive transmission overhaul.