VW Taigo Trans Issues: Strange Shifts & Warning Lights

Had similar symptoms with a 2018 VW T-Roc. The transmission behavior matched exactly what you describe, rough shifting, grinding, and emergency mode activation. Initial diagnostics pointed to radiator coolant issues, but the real problem was a faulty transmission control module connector. The main cause was corrosion in the wiring harness connecting to the transmission control unit. This triggered false readings about transmission fluid temperature and pressure, making the system think there were radiator pressure problems. After proper leak detection tests, we confirmed the radiator and cooling system were actually fine. The repair involved cleaning the connector pins and replacing the damaged wiring section. While not a major mechanical repair, it required specialized diagnostic equipment to properly identify the root cause. The transmission needed a complete electronic reset after the repair. Key warning signs to watch for: Transmission warning light coming on during specific weather conditions, Inconsistent behavior between cold and warm starts, Error codes related to transmission temperature sensors, Oil cooler temperature readings showing impossible values Would suggest getting a second opinion, specifically requesting a full electronic diagnostic scan rather than assuming its a mechanical transmission or cooling system issue.

Thanks for confirming this. Just had my VW Taigo repaired for nearly identical issues with the transmission warnings and rough shifting. The cooling fan was also making strange noises which initially made the shop suspect radiator coolant problems. After checking for coolant leaks, they found the same connector issues you mentioned. Curious how much you ended up paying for the full repair? Also wondering if youve had any transmission problems since getting it fixed? My car has been running fine for 2 months but Id like to know what to watch out for in case the symptoms return.

Thanks for asking about the repair costs. The connector repair on my T-Roc cost 95€, which covered fixing the faulty wiring connection to the transmission control unit. The cooling fan noise and transmission warnings completely disappeared after addressing the connector issue. The pressure sensor readings returned to normal once the cable connection was properly sealed and cleaned. Running the pressure gauge tests afterwards confirmed everything was working correctly, no more false readings triggering the transmission warnings. Since the repair, the transmission has worked flawlessly for over a year now. No more rough shifting or emergency mode activations. The key is keeping an eye on the temperature readings, they should stay consistent during normal driving. If you notice the readings becoming erratic again, it could indicate the connector needs attention. The leak detection tests also confirmed the coolant system was functioning properly, which helped rule out any actual radiator issues. Regular checks of the coolant level can help catch any potential problems early.

Thanks everyone for the helpful replies. Just got back from the mechanic where they fixed my Taigo. The repair cost was 120€ including the diagnostic work. After running pressure gauge tests, they found corroded wiring near the transmission control unit, exactly as described. The mechanic cleaned the connections and replaced a small section of damaged wiring. They also checked the cooling system thoroughly since the cooling fan was making odd noises. The transmission is now shifting smoothly again with no warning lights. The grinding noise is completely gone and the emergency mode hasnt kicked in since the repair. They recommended checking the coolant level monthly just to be safe, even though no cooling system issues were found. Really relieved it wasnt a major transmission repair. Will keep monitoring for any returning symptoms but so far the car is running perfectly after 2 weeks.