P2181 Code – Meaning, Causes, Symptoms (& How To Fix)

Learn what the P2181 code means on your code scanner and how to fix it. We’ll also cover a few troubleshooting tips that you can use today!

P2181 Code

When there is engine trouble with your car, it can be confusing and difficult to figure out, especially if you notice the P2181 code during your scan. What does this code mean and how can it be repaired quickly.

We take a closer look at the P2181 trouble code. Our guide shows you what it means, what faulty parts are causing it, the symptoms it can present and we give you some possible fixes. 

Code P2181 Definition

P2181 – Cooling System Performance

What Does the P2181 Code Mean?

The P2181 diagnostic trouble code indicates that there’s an issue with the cooling system performance. Sadly, there’s no specific part that is highlighted with this fault. This code isn’t common, with many manufacturers not listing it at all. It’s most prevalent with Chrysler models.

P2181 sets in the computer when the radiator coolant is either too cold or too hot. This temperature is detected by the Powertrain Control Module (PCM) and an alert is set if it is beyond the normal parameters. 

P2181 Trouble Code Symptoms

Depending on what is failing in the cooling system, there could be a variety of symptoms that occur. Either way, you’re likely to see some strange readings of the engine temperature gauge and the warning light may also come on. 

Here is the list of symptoms you might notice:

Causes of the P2181 Code

The causes of the P2181 trouble code will differ depending on the vehicle. There is a long list of possible causes, which is why a proper diagnostic inspection needs to be done to determine the underlying issue. 

Here are a few of the possible causes:

How Serious is the P2181 Code?

Medium – If the engine is running cold because of the fault, there isn’t as much danger involved. The cold engine isn’t going to impact the health of the engine as much as it does the fuel economy. At worst, you are going to spend more to keep the vehicle running.

On the other hand, it’s hazardous to run the engine hot. If you allow the engine to overheat, it can cause permanent damage to the cylinders and pistons. This damage is unrepairable, leading to a possible engine replacement. 

What Repairs Can Fix the P2181 Code?

After you perform the diagnosis, you will be able to figure out what’s going wrong with the cooling system. In some cases, one of these repairs might be the answer you are looking for.

Here are the top fixes to the P2181 trouble code.

  • Top off coolant
  • Thermostat replacement
  • ECT signal circuit repair
  • Engine coolant temperature (ECT) sensor replacement
  • Water pump replacement
  • Cooling fan replacement
  • Reprogram/replace PCM

Common P2181 Diagnosis Mistakes

There are multiple steps you must take to determine what’s wrong when the P2181 trouble code shows up. You can follow the steps we have outlined to diagnose it as a professional technician would.

However, many novice mechanics open the radiator cap with the engine running or when the motor is hot. If you do this, serious injury can occur, so it’s very important you wait until the engine is completely cooled off before taking the cap off. 

How to Diagnose the P2181 Trouble Code

You want to fix the P2181 trouble code as quickly as you can to prevent other damage. However, you don’t want to simply throw parts at the system and hope they work. Instead, you need to perform a series of diagnostic steps to determine what’s wrong.

Here are the steps that professional mechanics will use:

  1. Check all of the trouble codes. Sometimes, multiple codes will be present, thereby leading you in the right direction.
  2. If there are a lot of codes present, go ahead and clear them. Test drive the car until the Check Engine Light comes back on. Rescan the system for the most current codes.
  3. If the engine runs cold, you may choose to replace the thermostat.
  4. If the temperature rises when you idle or stop the car, the problem could be the radiator fan.
  5. When the engine runs hot, you have a lot more that could be going wrong. To start, you want to make sure the right amount of coolant is in the system. Although, you should never open the radiator cap while the engine is hot. If the levels are low, add more coolant.

For detailed instructions on how to test the multiple cooling system parts, you want to reference the car’s service manual. This manual will give you detailed diagrams and the steps you should follow. 

READ MORE FOR DIAGNOSIS: 9 Causes of an Overheating Car Engine (& How To Fix)

Estimated P2181 Repair Cost

Depending on what you find is wrong with the system, you have varied repair costs involved. Here are some estimates that include both parts and labor. 

  • Top off coolant – $10-$45
  • Thermostat replacement – $150-$300
  • ECT signal circuit repair – $100-$400
  • Engine coolant temperature (ECT) sensor replacement – $150-$300
  • Water pump replacement – $400-$700
  • Cooling fan replacement – $450-$650
  • Reprogram/replace PCM – $50-$2,000

Mechanics Tips about the P2181 Code

With the P2181 trouble code, you might see a couple of other DTCs, both of which can help you determine what’s wrong. Here are the most popular:

If you use these codes in conjunction with the symptoms, you might be able to diagnose the issues faster.

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Magnus Sellén
Written by:

Magnus is the owner and main author of Mechanicbase. He has been working as a car mechanic for over 10 years, and the majority of them specialized in advanced car diagnostics and troubleshooting. Certified Automotive Diagnostic Technician.