Audi A1 Transmission Sensor Triggers Multiple Failures

I had a very similar issue with my 2019 Audi A3. As someone with moderate experience working on cars, I initially thought it was a major transmission failure, but it turned out to be much simpler. The transmission sensor was reporting errors due to low gearbox oil level. The pressure gauge readings were off, triggering the limp mode and warning lights. My workshop diagnosed it as a transmission sensor fault initially, but after a thorough check, they found the oil level was significantly below minimum. The fix included: Full transmission oil level check, Replacement of contaminated oil, Sensor recalibration, Computer system reset Total cost was 365 Euro including parts and labor. The grinding noise and rough shifting disappeared completely after the repair. To provide more specific advice about your A1, could you share: Current mileage, When was the last transmission service, Are there any oil spots visible under the car, Did the issue start suddenly or develop gradually These details would help determine if your case is similar to what I experienced with my A3.

Last service was completed at 60000 KM with full transmission oil change. The pressure sensor readings began fluctuating about 2 weeks ago, causing transmission issues to appear gradually. The service center cleared the fault codes but they returned after 3 days. A key detail I forgot to mention, the transmission pressure switch shows inconsistent readings even when the engine is cold. The current mileage is 65323 KM, and Im really hoping this isnt a sign of major transmission failure. Already spent 450 Euro on diagnostic tests. The oil sensor readings seem normal when checked separately, which makes this even more confusing. Has anyone tried replacing just the pressure sensor assembly without a full transmission overhaul?

Having gone through this exact scenario with my A3, I can confirm replacing just the pressure sensor assembly worked perfectly. After my initial oil-related fix, I actually encountered a similar issue a few months later where the pressure switch showed erratic readings. The transmission pressure sensor is a common failure point in these models. The inconsistent cold readings you mention strongly point to a faulty pressure switch, which matches my experience exactly. The oil sensor might show normal because its a separate component from the transmission pressure sensor system. In my case, replacing the transmission pressure sensor assembly fixed: The erratic pressure readings, Warning light issues, Rough shifting problems, Emergency mode activation The repair cost was 280 Euro including parts and labor. Much cheaper than a transmission overhaul and resolved all symptoms. Since your mileage is relatively low and the transmission oil was recently changed, I would definitely try the pressure sensor replacement first. Make sure they test the new pressure switch thoroughly after installation, mine needed a specific calibration procedure to work correctly with the transmission control module.

Thanks for the detailed feedback. Your A3 experience sounds exactly like what Im dealing with. Ive scheduled a pressure sensor replacement for next week, they quoted 295 Euro for parts and labor, which seems reasonable compared to your repair cost. The service center confirmed they will perform the calibration procedure after installing the new transmission pressure sensor. They also mentioned theyll do a complete system diagnostic to ensure no other transmission sensors are affected. Really relieved this might not require a full transmission overhaul. The fact that your car showed the same symptoms with cold engine pressure switch readings makes me confident were dealing with the same issue. Will update once the repair is done to confirm if replacing the pressure sensor assembly solved the problem. For now, Im keeping the car in eco mode to minimize stress on the transmission until the repair. Thanks again for sharing your experience, saved me from potentially unnecessary major repairs.