This morning when starting my octavia 2.0 tdi the red coolant warning light illuminated. I checked the level in the tank and it was as it should be. I turned the engine off then on again and the light's not gone out. The car's running perfectly (the air temp was minus 1 at the time). Any ideas?

Thanks.

Mine has been doing the same in the cold weather once the coolants warm I can turn it off and restart the engine it stays off. Guessing a new sensor is required but ive just been ignoring it.

Take the cap off the expansion bottle and give the two metal prongs of the sensor a scrape with a screwdriver.

Thanks trundlenut !