Hello, I have a 2002 A4 1.8TQ and I am getting the above code. On start-up the front fan in the engine bay (radiator fan or just next to it?) runs and stays on while the car is on. The temp gauge in the dash is always at C or just above no matter how long the car has been on or running (4.5 hour drive for Thanksgiving and never moved toward the center).

I read a similar post and determined that it may be the coolant sensor so I replaced that the other day but I am still getting the code. I have also read that if you changed the sensor and it isn't fixed that it may possibly be the thermostat.

My question is, do I just need a new thermostat due to these symptoms or is there a possible "fix" to the thermostat's behavior that may lead to the solution? I have read about it being "stuck open" (although that seemed to be with overheating so possible mine is "stuck closed"?) and causing issues with the coolant system/temp gauge/etc so I was curious as to my best course of action.

Any help/advice is appreciated. I am a fairly intelligent guy but not so much when it comes to under the hood of a car so feel free to talk to me like you would a 12 year old to save yourself numerous return questions.

Thank you much.

 

Bump...anyone?

 

Currently having the same problem on mine and replaced the sensors and the CEL comes back. Fan still starts from first start up when the car sat overnight. I also had the problem of car stalling out until it got a little warm. Still trying to solve.

 

Generally the way you want to go at this....

is replace the coolan temp sensor

then the thermostat

then the water pump....

those are the only three things that cause this fault.... and they are listed this way due to price and ease...