P2181 Audi/VW Fault Code - Thermostat
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P2181 Audi/VW Engine Code – Diagnosis & Repair

Chandler Stark

Meet Trey

Trey is an automotive enthusiast and has a huge passion for Volkswagen and Audi vehicles of all kinds. His enthusiasm started with the MK5 GTI, and he has massively expanded his knowledge over the years. When Trey is not delivering high-quality and in-depth content, we can usually find him working in his garage on his modified Genesis coupe. Trey created VW Tuning several years ago, and he is the primary visionary behind the content.

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P2181 Audi/VW Fault Code: Coolant Performance Issue

For Volkswagen’s and Audi’s, a P2181 fault code is rather common because the cooling system parts are very similar. If you plug in an OBD-2 scanner and get P2181, you will more than likely see “P2181 – Cooling System: Performance”. What does this mean exactly because the cooling system includes many engine components? Well, this guide will walk you through what you can check to alleviate this fault code. We will be writing this for the 2.0t TSI or FSI engine because it is probably the most common engine when it comes to VW and Audi. If you need assistance in searching for parts/guides, leave a comment below and we will assist you in any way we can.

P2181 Audi/VW Symptoms

  • Check Engine Light (CEL) illuminating
  • Coolant light illuminating
  • Car overheating
  • Engine not reaching optimal temperature levels (Generally 190)
  • Low or no heat
  • Rough idle
  • Engine stalling

Causes of P2181 Engine Code

  • Bad Coolant Temperature Sensor (CTS)
  • Stuck thermostat
  • Faulty water pump
  • Failed cooling fan or cooling fan control module
  • Bad electrical connector somewhere from the CTS to the ECU

We know this is a bunch of causes, but we’ll break it down to where you should start first. The most common causes for this engine code is going to be the CTS or the thermostat. That’s not to say those are the only things you should check, but those are the main solutions when it pops up.

How to Repair an Audi/Volkswagen with a P2181 Engine Code

We would advise starting with the two main causes: bad CTS and stuck or bad thermostat. If you are wanting to take your car into the shop to get a diagnosis, remember you would be paying an hour of labor just for diagnosis, which can be anywhere from $75 – $150. On top of that, you will be paying for the parts needed to resolve this issue. So all in you could be looking at anywhere from $100 – $400 depending on what is causing the code to pop.

Replacing the CTS on Your Volkswagen 2.0t

This should be the first test because it is cheap and an easy DIY. We would say maybe 50% of the cases with this engine code is resolved by just replacing the coolant temperature sensor.

Buy Here: VW 2.0T CTS Replacement
DIY Difficulty: Easy

Replacing the Thermostat on Your Volkswagen 2.0t

The other 40% of the cases with this engine code is resolved by replacing the thermostat, so this should be your second test. We’ll show you guides on how to diagnose and replace if need be. To diagnose if it is a faulty thermostat or water pump do these simple steps. What happens is that the thermostat either gets stuck open or stuck closed, with stuck closed being the most common. With it being closed, it would overheat your engine.

Buy Here: VW 2.0T Thermostat Replacement
DIY Difficulty: Intermediate

Replacing the Water Pump on Your Volkswagen 2.0t

The next few replacements/diagnosis are rare to cause the P2181 engine code for your Audi or VW, but they can still cause it. A water pump transports coolant from the radiator to the engine ensuring engine temperatures are running at optimal levels. The water pump plays a big part in the cooling system of the engine. So if your engine is overheating and throwing this code, it is either your water pump or thermostat.

Buy Here: VW 2.0T Water Pump Replacement
DIY Difficulty: Intermediate
Replacement Written DIY Guide

Replacing the Cooling Fans on Your Volkswagen 2.0t

Again, this is a rare cause of the code but is possible. If you turn on your vehicle and turn on your A/C and notice these fans aren’t spinning, there’s a high possibility you need to replace these.

Buy Here: VW 2.0T Cooling Fans Replacement
DIY Difficulty: Intermediate


To conclude, if you are getting the P2181 engine code, you can drive on it but only for a short time period. It is something that should be addressed ASAP because it could lead to major engine damage if ignored. Like we stated above, we did this for the 2.0t engine, but if you are getting this code on another engine, please reach out and we can assist in looking for guides or parts! We hope this write-up helps you and your vehicle.

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  1. I have a 2014 Audi Quattro turbo 2.0 I change the water pump I change the temperature sensor is still the check engine light is coming out in this market P2181 see what you could do for me What could be wrong

  2. Yeah, but also check if u have two sensors.theres 3 including level Of coolant. vw 13″
    Check manual

  3. I have a 2004 VW New Beetle 2.0L and I’m coming up with these issues. Would these fixes apply to my car (because of its age)?

  4. P2181 ….. 2009 VW Passat
    Changed sensor, and new thermostat and engine light keeps coming on !?
    Temperature gauge stays consistent and safe. Heater/a/c works fine !?

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