Question

What's the engine code P2181 on my 2005 Volkswagen Passat 1.4L?

Answer 1

Possible causes include (but are not limited to) a bad coolant temperature sensor, stuck thermostat, bad waterpump, bad electrical connector somewhere.

Did your car overheat?

turn on in AC and see if the fan is working

Answer 2

P2181 VOLKSWAGEN Code - Cooling System Performance
Read more: https://www.autocodes.com/p2181_volkswagen.html