Anyone know what issue code P2181 could be?
I received the same error code on my 06 2.0T and the tech found the thermostat sticking. Per tech, "Found 1 DTC P2181 for cooling system malfunction, checked measuring values, found thermostat sticking open. Recommendation is to replace thermostat with housing."
I had them replace the thermostat and coolant temp sensor for $395.
If you replace the Tstat, go ahead and replace the ECT in the housing @ the Tstat.
VW actually recommends that if you replace the Tstat, you should replace BOTH ECTs, and repine BOTH connectors.
The sensors are cheap, since you will be in there anyway, just go ahead and replace the one. If you see any further MALF in COOLING issues, just replace the other one at that point.