05 B6 1.8t fans on on start up

[jarrodblake]

I have a 05 B6 1.8t. The fans turn on on start up and stay on. I have replaced the sensor on the lower hose and on the back of the head with audi vw oe sensors from ecs tunning. The check engine light code is p2181. is there a way I can trouble shoot what part has failed? A little more info I drive 15 minuets to work, by the time I get there then temp gauge is at 1/4 or a little under. The ecu temp is at 176.

[EuroxS4]

Founds like a bad FCM or issue with control wire going to the ecm.

[old guy]

Your code indicates a "Performance Malfunction In The Cooling System" This occurs when the ECM isn't seeing the temperatures it expects to see. This code does not indicate any type of electrical component failure.

The default position for this code is to run the fans all the time. The ECM knows something is wrong so it acts to protect the engine.

I suspect your problem is being caused by a sticking thermostat. for more detail read posts 14 and 22 in this thread: Clicky click®️

[EuroxS4]

Cooling system performance is always a bad thermostat.

[Keef sweat]

It’s the fuse that goes to the central comforts/ the climate control fuse.
When the fuse pops, it throws fans on on startup.


Sent from my iPhone using Audizine Forum

[Puddin Tane]

It’s the fuse that goes to the central comforts/ the climate control fuse.

Fuse #24 in the main fuse panel, far left of dash (uppermost and left-most of the larger size fuses), should be 20 amp in an '05. If blown, check for standing water or moisture under the floor of the passenger side footwell (where the climate control module (CCM) is located), which would in turn point to blockage of the battery tray drains or blocked or leaking sunroof drains. May need to replace CCM.

[EuroxS4]

Thermostat is your issue. Change thermostat and all will be good.

[canonball]

Any updates on this? I'm having a similar issue (along with some other issues ), curious to know what you got figured out, op.