Driving down the 401 with my heat on in -12 weather.... my check engine light came on at the same time as my coolant temp hit just below 60. Turn the heat off and it gets up to about 75, but thats as high as i could get it to go. Its the second time it has done this, and it doesnt make me very happy. The light stayed on untill the weather hit about 0 and i was doing city driving. Anyone else have this problem and know the solution?

Its a 2000 a4 b5 2.8

 

Coolant temp sensor, VAGcom it though.

 

Anyone in the kw area able to help me out with some vag magic? I have beers!

 

there is plenty of manuals on net

 

try pdfs too

 

that doesn't really sound like a temp sensor to me. Sounds like a Thermostat issue. If it is stuck open the coolant won't get a chance to heat up.

 

i asked ..with same problem i changed the thermostat and still have cold coolant ,so it might be sensor you think?

 

I guess it could be, does your heater blow hot?

 

mostly cold