What Does the Engine Code P2181 Mean?

A P2181 engine code indicates a problem with your vehicle’s cooling system.
Written by Rachel Rigolino
Reviewed by Melanie Reiff
If your vehicle is showing code P2181, it indicates a problem with the cooling system. Likely, you will see other codes as well because having a P2181 code alone is considered somewhat rare. Fix the problem as soon as possible so that you do not run the risk of having your engine overheat. 
An OBD-II code reader reads your car’s computer and tells you what problem is causing your
check engine light to come on
. This is an important first step in determining the problem, but keep in mind that you may need the help of an expert to identify the specific cause(s) of a P2181 engine code.
Taking care of your
car insurance
can be just as much of a hassle as dealing with
car maintenance
. But it doesn’t have to be. The licensed broker app
will not only find you great rates on car insurance, but we’ll tell you everything you need to know about a P2181 code and what to do about it. 
Let Jerry find your price in only 45 seconds
No spam · No long forms · No fees
Find insurance savings

What does the engine code P2181 mean?

Your engine’s computer monitors the coolant temperature levels in your radiator and engine. When the coolant temperature becomes too hot or too cold, it can trigger a P2181 engine code.  

How much will it cost to fix?

Diagnosing a P2181 code will typically involve one hour of labor costs. 
 After the problem has been diagnosed, your mechanic should explain exactly what is causing the P2181 code and what parts and how much labor will be needed to fix it. While some problems may be fairly easy to address, others require more intensive labor.  
Costs vary depending on what needs to be replaced. For example, replacing a bad
Engine Coolant Temperature Sensor
costs between $392 to $426. If your
vehicle’s thermostat
needs to be replaced, however, this process typically costs between $470 and $505

What can cause the P2181 engine code?

Some common causes include:
  • Engine coolant is too low or too dirty
  • Engine thermostat needs to be replaced
  • Radiator cap needs to be replaced
  • Leaking hoses 
  • Faulty sensor
Other less common causes include:
  • Electrical problem
  • Problem with fan clutch
  • Problem with the head gasket

Common symptoms of the P2181 engine code

Your temperature gauge on your dashboard may show that your engine is running either too cold or too hot. Or it may show fluctuations. (Of course, when your car has been sitting and becomes cold, the gauge will read cold until the engine heats up.)
If your temperature gauge is reading high, this is a serious problem, and it indicates that the
car is overheating
. Pull over to the side of the road and allow the engine to cool before driving home or to a service station. You will need to fix the problem before continuing to drive the vehicle.

How serious is the P2181 code?

An engine that is running cold can cause problems with fuel efficiency and heating the interior of the car. This problem should be addressed, but it’s not an emergency.
While an engine that is running cold may not be an immediate problem, one that is overheating can cause serious damage to the engine. 
This is why it is important to address coolant system problems as soon as possible. Overheating can cause catastrophic problems to your engine.

Can I fix the P2181 engine code myself?

Sometimes, fixing the underlying problem can be fairly simple. Here are some common causes of the P2181 code that some car owners may be able to fix themselves. 

Replace the ECT sensor

Newer cars have Engine Coolant Temperature (ECT) Sensors that sometimes go bad. After removing the ECT sensor from the engine, use a multimeter to determine whether the sensor is still working. If it is not, replace the sensor.

Drain and Replace the Engine Coolant

If you determine that your ECT sensor is working, try draining and replacing the coolant in your radiator. This process involves removing the radiator drain plug or hose and draining the old coolant, so be prepared to catch the coolant and dispose of it properly. Then, add fresh coolant. 
This process can take some time because you will need to make sure there is no air in the system.

Replace the Thermostat

If you have checked the thermostat and found it is no longer working, it must be replaced. In many cars, this process is fairly simple. However, you must be careful to take out the bad thermostat and replace the new one correctly. Follow your car manual’s instructions.

Finding insurance for your vehicle

While diagnosing problems with your car’s engine can be a hassle, finding insurance savings shouldn’t be. 
If you want to save money on car insurance, the
app is a good place to start. A
trustworthy licensed broker app
, Jerry does all the hard work of finding cheap quotes from the top name-brand insurance companies and buying new car insurance. Jerry will even help you cancel your old policy.
No long forms. No calling around. No hard work. Just savings. The average Jerry user saves $887 a year on car insurance.
is a super straightforward process, and at each step, you can see exactly what coverage you’re paying for. Thanks to Jerry, I’m paying $900 less each year while keeping full coverage for my new car!” —Martin H.
Jerry sends free alerts to keep your car up-to-date so you can avoid costly repairs
* checking your rate won’t affect your credit score
Get ahead of my car maintenance
* checking your rate won’t affect your credit score
Estimate your repair costs for free with GarageGuard™
Simplify your car maintenance with Jerry.
Try GarageGuard™

Easiest way to compare and buy car insurance

No long forms
No spam or unwanted phone calls
Quotes from top insurance companies
Find insurance savings