VW Touran Trans Warning: Common Sensor Issue Or Worse

Had almost the exact same issue with my 2016 VW Tiguan with the automatic transmission. Being someone with some mechanical experience, I initially suspected sensor problems too. The transmission warning light and emergency mode turned out to be triggered by low transmission oil level. The temperature sensor was giving false readings because it wasnt properly submerged in the fluid. Workshop did a complete diagnostic and found small leaks causing gradual oil loss. The repair involved: Full transmission oil level check, Leak detection test, Replacement of worn transmission seals, Fresh transmission oil refill, Reset of transmission control unit Total cost was 365€ and completely resolved the grinding sounds, rough shifts, and warning lights. The transmission has been working perfectly since then. Before suggesting more specific solutions, could you share: Current mileage, When was the last transmission service done, Are there any visible oil spots where you park, Did the issue start suddenly or develop gradually The automatic transmission and its sensors are quite sensitive to oil levels, so its worth checking this first before replacing parts. Regular transmission maintenance helps prevent these issues.

Thanks for sharing the details. My Touran has 40059km and just had its scheduled service last month. The issue started gradually over the past few weeks. No oil spots visible under the car, but the gear shifting problems got worse, especially when the transmission oil was cold. The gearbox sensor warnings appeared shortly after. My transmission has been pretty reliable until now, with no prior issues during normal driving. The service records show regular transmission oil changes according to schedule. After reading your experience with similar symptoms, I will make sure the workshop checks the transmission oil level and seals first before jumping to sensor replacements. The temperature sensor readings might indeed be affected by low fluid levels as you mentioned.

Thanks for those additional details. The symptoms you describe, especially the issues being worse when cold, match my Tiguan experience pretty closely. Since your transmission problems developed gradually like mine did, and theres no visible leakage, you might have a slow internal leak thats hard to spot. The temperature sensor and transmission oil sensor systems often trigger warnings when fluid levels drop below optimal range. The fact that your Touran just had service but the problems persisted suggests the transmission oil level wasnt properly checked or topped up. Sometimes small leaks get missed during routine maintenance if they dont specifically pressure test the transmission system. The overheating problems I experienced were actually caused by low fluid, not a faulty temperature sensor. When the transmission runs low on oil, the remaining fluid overheats more easily, causing those rough cold shifts you mentioned. Definitely have them: Perform a proper transmission oil level check with the car at operating temperature, Run a transmission sensor diagnostic while monitoring fluid temps, Check all seals and connection points for seepage, Test the transmission oil pressure My repair cost of 365€ included parts and labor, yours might vary but checking fluid levels first could save replacing sensors unnecessarily.

Thanks for the thorough response. This definitely helps narrow down where to look first. Based on your similar experience, I will have the workshop focus on checking the transmission oil level and potential internal leaks before replacing the temperature sensor. Those cold shifting symptoms do sound exactly like what you encountered with your car. The transmission has always been reliable until these issues started appearing gradually. Since my last service was recent but did not resolve the problems, I agree they may have missed checking for slow leaks during routine maintenance. I will specifically request: Complete transmission oil level inspection at operating temperature, Seal and connection point leak testing, Transmission pressure diagnostics, Sensor function verification This approach makes more sense than immediately replacing parts. Will update once the workshop diagnoses the actual cause. The estimate of around 365€ for addressing similar automatic transmission issues gives me a good reference point for the potential repair costs.