Hope this helps - I had a similar problem on my VR6 - coolant light flashing when oil temp was normal and no other signs of overheating. After replacing the sensor and testing out the wiring it turned out to be the temp gauge itself was faulty. The little metal strip that moves the needle looked burnt and was operating ok at lower temps but shooting up to beyond max at normal temp and triggering the light as well. Replacement temp gauge from passat cluster solved it for me.
Yeah that's exactly the same way I resolved the issue with mine.
Temperature warning light
in Engine Bay
Posted
Yeah that's exactly the same way I resolved the issue with mine.