VW Jetta Hybrid: Flashing CEL Points to Bad Temp Sensor

As a VW Passat GTE Hybrid (2017) owner, I dealt with nearly identical symptoms. The flashing check engine light combined with poor performance and increased fuel consumption pointed to a faulty exhaust temperature sensor. The heat sensor replacement turned out necessary after the diagnostic scan confirmed the malfunction. The repair required removing parts of the exhaust system to access the temperature sensor. During inspection, the mechanic found minor exhaust leaks near the sensor mounting points, which needed welding. The complete car exhaust repair included both sensor replacement and sealing the leaks. The engine management system relies heavily on accurate temperature readings from these sensors. When they fail, the car runs in a safe mode, deliberately reducing performance and efficiency. This is a serious issue that needs prompt attention since it can lead to catalytic converter damage if left unrepaired. Common signs that confirm a bad temperature sensor: Flashing engine light, Rough idle, Poor acceleration, Increased fuel use, Failed emissions test Recommend getting a proper diagnostic scan first. The specific sensor location and type varies between VW hybrid models, so proper identification is crucial before any parts replacement.

Thanks for that detailed explanation of the exhaust temperature sensor issue. I had exactly this problem with my 2015 Jetta last winter. The engine management system kept throwing codes and my fuel economy was terrible. Been thinking about posting here to ask how your repair held up. Did any other sensor issues pop up since the replacement? Also curious about the final cost of your fix if you dont mind sharing. Always good to have a reference point for these repairs since prices for heat sensor replacements seem to vary quite a bit between shops.

My exhaust system repair has held up perfectly since getting it fixed. The faulty exhaust temperature sensor replacement completely resolved the temperature fluctuation issues and engine performance returned to normal. The mechanic found a small leak during the repair which needed attention, bringing the total cost to 265€ for the complete exhaust system service. Have not experienced any other sensor problems or emission control warnings since the repair. The engine management system readings are now stable, fuel consumption is back to normal levels, and the check engine light has stayed off. The temperature sensor repair proved to be a straightforward fix once properly diagnosed. Having both the sensor replaced and the leak addressed in one service visit likely prevented future exhaust system complications. The investment was worthwhile considering the improved performance and efficiency.

After reading all this helpful info, I finally got my Jetta fixed last week. Took it to a shop specializing in VW emission control systems. The diagnostic scan confirmed the exhaust temperature sensor failure. Total repair came to 320€ including labor and parts. The mechanic showed me the old sensor, completely corroded from exhaust heat exposure. The engine management system immediately responded to the new sensor. Check engine light cleared up, fuel economy improved, and the car runs smooth again. Really glad I got a proper diagnosis first instead of letting shops guess at the problem. Saved money by targeting the specific sensor replacement rather than replacing multiple parts unnecessarily. No more performance issues since the repair.