Failing VW Tiguan Transmission, Cooling System Alert

I had a similar issue with my VW Touareg 2011 diesel last year. Having some experience with transmission problems, I first suspected a major transmission failure, but it turned out to be much simpler. The issue was related to the pressure sensor connection at the transmission. The cable connector had corroded and was causing faulty readings, triggering the emergency mode. The transmission cooling system was actually fine, but the car was getting incorrect pressure readings. My workshop did a thorough leak detection test to rule out any issues with the oil cooler or cooling fan system before diagnosing the actual problem. They found the faulty connection, cleaned the contacts, and replaced the damaged connector. Total cost was 95€ for parts and labor. Before suggesting more specific solutions, could you share: Current mileage on your Tiguan? What error codes are you getting? Have you noticed any transmission fluid leaks? When did the grinding noise first start? This information would help determine if your issue matches what I experienced or if its something different in the transmission system. The car overheating symptoms you mentioned particularly concern me, as this could indicate a separate issue from what I dealt with. Its worth checking both the transmission and engine cooling systems independently.

Thanks for describing your transmission issue. My Tiguan had its last service at 135500km, and since then, I have not experienced any transmission fluid leaks. Looking at the error codes from my diagnostic tool: P0722, Output Speed Sensor Circuit No Signal P0733, Gear 3 Incorrect Ratio P0715, Input/Turbine Speed Sensor Circuit The grinding noise started about 2 weeks ago, initially only when shifting from 2nd to 3rd gear, but now occurs during most gear changes. The pressure gauge readings show inconsistent values compared to the workshop manual specifications. The cooling system appears to be functioning normally with no visible leaks or temperature spikes. However, the radiator repair shop suggested the transmission oil cooler might be partially blocked, affecting pressure readings across the system. A pressure sensor replacement was recommended, but I would like to confirm if this matches others experiences before proceeding with repairs.

Thanks for providing those details. Looking at your error codes and symptoms, your situation seems more complex than what I encountered with my Touareg. While my issue was isolated to the pressure sensor connector, your multiple error codes suggest potential issues with several transmission components. The P0722 and P0715 codes typically indicate problems with speed sensors, not just pressure-related issues. In my case, when the pressure gauge readings were inconsistent, it was purely due to that corroded connector. Your situation showing multiple speed sensor errors could mean either: 1. A more serious transmission fluid circulation problem affecting multiple sensors 2. Wiring harness damage affecting multiple sensor circuits 3. Failed speed sensors The transmission oil cooler blockage theory makes sense given these symptoms. When my cooling system was tested, the workshop found that poor circulation through the oil cooler can cause similar pressure fluctuations and sensor errors. Given the grinding noise and error combination, I recommend: Full transmission fluid analysis (around 150€), Pressure testing of the complete cooling system, Speed sensor circuit testing, Oil cooler flow test This diagnostic approach will cost more initially (typically 250-300€) but prevents replacing parts unnecessarily. My initial attempt to just replace the pressure sensor would have been a waste in your case.

Thanks for the comprehensive breakdown. After getting your feedback and comparing it with my symptoms, I think I will proceed with the full diagnostic testing rather than jumping straight to the pressure sensor replacement. I will schedule the transmission fluid analysis and complete system pressure testing first. Given that the grinding noise has spread to multiple gears and the error codes point to speed sensor issues, your suggestion about checking the entire system makes more sense than my initial focus on just the pressure sensor. The 250-300€ diagnostic cost is higher than I hoped, but its better than replacing parts blindly. I will have them check the oil cooler flow and speed sensor circuits as part of the testing. The radiator repair shop can handle the cooling system evaluation while they check for any blockages. Will update once I have the test results and know exactly whats causing these transmission issues. The multiple error codes definitely suggest this is more complex than a simple sensor problem like in your case.