Temperature light stays on when cold out?

[Kayakkermit]

I imagine this has been covered, I just haven't found it in a search.
Last night when both my wife and I left work, we both had the temperature light come on in both the Jetta's when we started them.
Mine stayed on for about 3 minutes, but hers stayed on the entire 50 minute drive home.
I'm sure it has something to do with the cold weather, but shouldn't her light have gone off by that point? Why do they come on (what are they telling me)?

 

[Joe_Meehan]

I would suspect a stuck thermostat. They are not expensive so I would have it replaced.

You did not say how cold it was, what model TDI you have, how old it is or how many miles on it. All that information and any repair history would help us make better guesses.

 

[Variant TDI]

The coolant light coming on in very cold weather is fairly common.

Try a search on "Coolant Light"

 

[compu_85]

Check your coolant level. When it is low the coolant light blinks red, and the cluster beeps at you.

-J

 

[Kayakkermit]

Yep, it was the coolant level.
I had put zerostarts in about a month ago, and had topped the overflow tank up on both cars, but I guess they must have both had an air pocket that "burped" and brought the collant levels down to just the point that it only triggered the sensor when it was so cold out.
My wife actually thought that might be the case also, and we found that Friday morning.... Friday afternoon we each stopped by the dealer who topped up our tanks with the correct coolant as a free service.
Kudo's once again to Woodstock VW, one of the good guys in a sea of poor dealers.

 

[Charsdst]

Kermit, I read somewhere that you should tighten the hose clamps again several weeks after installing a zerostart. They tend to loosen up a bit, which could cause your low coolant level inticator to come on.

 

[Beerme]

Well Kudo's to Mrs Kermit for nailing the diagnosis, you'll have to be a bit more genuine with your "yes dear, ok dear" now ....