richierichs3

Hi guys and girls, changed my battery on my S3 8p. Since then every time i turn the engine off and after a couple of seconds both fans kick in full on and last any where between 20 and 90 seconds depending on the drive. Now ive had the car for 2.5 years and its never done this.
My question is has anyone had this problem and how to fix it?

Thanks Richard

beep-beep

fans are controlled by the coolant temperature sensor. If the coolant is too hot after you stoped the engine, the fans will keep blowing until the temperature drops. So usually you get the afterrunning of the fans in summer expecially if the AS was used and AC radiator is hot as well.
so keep an eye on the coolant temperature in the instrument cluster. If it does not behave correctly you will need to change the temperature sensor and or relay or thermostat.

the_duke

Step 1. pull codes via VCDS.

Buying parts when you have no idea what is wrong will be costly.

richierichs3

Ive had the codes checked and no faults and the temperate gauge is the same as before i changed the battery.
Im getting sick of the fans going full on for a couple of minutes after i turn the car off. The only time they dont go on if the engine doesnt get to full running temperate, like a short trip. Getting plenty of people saying your cars still running.

the_duke

How did you have the codes checked? Dealership with factory scan tool, Indie shop with VCDS, or a generic code reader? If it's the third one then you need to have the codes checked with the correct reader. Might also be necessary to monitor measuring blocks to see if readings are correct. Again something that can't be done with a generic reader.

richierichs3

Yes it was with a generic code reader. Ok thanks

richierichs3

Took it to a euro specialist today and he is going to quote me on a main fan control module to fix the problem.It showed up no faults. He has seen this on a few diesels. What do you think?

the_duke

Sounds reasonable to me assuming temp readings from the various sensors is correct. Temp sensors don't usually throw a code when they fail. You just get strange things like fans running when they shouldn't. Readings can be checked with VCDS. I'm assuming the tech did that and verified the temp sensor is good which would point to the fan controller.

richierichs3

He did and thats why he thinks its the fan controller. Ill keep you updated with the results. Fingers crossed

richierichs3

Got a quote from my mechanic $405. Do you know where i can buy one to do it myself besides Audi dealers?