How to Troubleshoot & Fix P2181 Jeep DTC Code? (Ultimate Guide)

The P2181 trouble code is considered serious, because the code indicates the cooling system in your engine might not be working properly, thus leading to engine overheating and further complications.

Therefore, you must troubleshoot for the specific reason for which the code is present and solve it. 

No worries, you’ll get to know all about the causes and their potential fixes to eliminate the P2181 code from your Jeep. 

What Does P2181 Jeep Code Mean?

Getting the diagnostic trouble code P2181 after scanning the OBD-II tool means something is wrong with the engine cooling system. 

It specifically denotes that the temperature of the coolant in your engine is either higher or lower than the manufacturer’s specified range, which is not ideal for the engine for best performance.

If you break down the P2181 Jeep code, you’ll get the following explanations about the issue.

  • P = This character indicates that the code is a powertrain code, which relates to the engine, emission, and transmission.
  • 2 = Manufacturer specific trouble code.
  • 1 = Engine cooling system performance.
  • 81 = Specific fault index. (In this case, 81 refers to a fault in the Coolant temperature that is not appropriate.)

P2181 Code: What Causes Error in Coolant System Performance on Jeep?

The P2181 code is a manufacturer-specific trouble code for Jeep vehicles. Different models of Jeeps, such as Liberty, Wrangler, Chrysler, etc., are often found with this code.

According to car complaints, in 2002,2006, and 2009 Jeep Liberty have been mostly reported with erratic cooling systems causing P2181. 

This DTC can get triggered by the PCM for various reasons. Some common causes are as follows: 

  • Low coolant 
  • Faulty ECT sensor
  • Short or open in the ECT sensor circuit and wiring issues
  • Open/Short or stuck Thermostat
  • Clogged radiator or failing water pump

How to Troubleshoot & Fix P2181 Jeep Code?

As you know, the P2181 Jeep DTC code can get triggered for single or multiple causes. Hence, pinpointing the causes is essential before attempting to fix the error code.

Now that you know the most probable reasons for the P2181 Jeep code, it’s time to troubleshoot the issues.

1. Check the Coolant Volume

Start with the simple one. Ensuring the volume of coolant or antifreeze is sufficient is the easiest and cheapest thing to do to avoid the P2181 Jeep code. 

The engine coolant temperature sensor (ECT) is responsible for monitoring the temperature of the coolant and sending this information to the engine control module.

If the coolant level is low, the sensor may not be fully immersed in coolant, which can cause it to send incorrect or out-of-range signals to the engine control module. 

This can result in improper engine cooling and overheating. Furthermore, the engine control module may store a trouble code P2181 when it senses a temperature fluctuation.

To prevent this issue, you must regularly check the coolant level in the engine and top it off as needed. Check for leaks surrounding connecting hoses, radiator, etc., which may cause a sudden drop in the coolant level.

Read Also: How to Troubleshoot and Fix P0562 Jeep DTC Code? (Ultimate Guide)

2. Replace the Engine Coolant Temperature Sensor

If the coolant level is optimum, it’s time to look further deep to solve the P2181 Jeep code issue. 

The Engine Coolant Temperature (ECT) sensor in a Jeep is used to measure the temperature of the engine coolant and send this information to the engine control module (ECM).

Afterward, the ECM uses this information to adjust the engine’s performance. Hence, a bad or faulty ECT sensor sends erratic readings, triggering the P2181 DTC code in Jeep. 

According to the complaints recorded in carproblemzoo, the Wrangler, Grand Cherokee, Liberty, and Compass had the most issues regarding P2181. 

And a bad ECT sensor is the culprit behind this occurrence. However, fixing the issue is very straightforward.

Take out the old sensor and check its resistance using a multimeter which should be around 2000-3000 ohms at ambient temperature. 

If the reading is not matched, you must replace the sensor with a new and compatible one.

You will get a new OEM ECT sensor for around $23-$28. Ensure clearing the code from the computer after replacing the ECT sensor. Go for a test drive and observe if the code pops back on the dash.

3. Check ECT Sensor Circuit for Shorts or Wiring Damage

Considering the ECT sensor is fine in your Jeep, let’s take a peek at the wiring harness that connects the ECT sensor to the ECM. In general, there are three wires in the connecting harness.

Pull off the harness and check if the wires are connected properly. If the wires are broken, all you need is to re-connect them. 

Furthermore, corrosion in the connecting pins can also trigger the P2181 Jeep codes.

You can use dielectric grease to get rid of the corrosion. Afterward, reset the code and inspect whether the problem is coming back.

Read Also: How to Troubleshoot & Fix P06DE Jeep Wrangler DTC Code?

4. Inspect For Open/Short Thermostat

The thermostat is responsible for regulating the engine coolant temperature by controlling the coolant flow to the engine. 

If the thermostat is open or shorted, it can cause the engine coolant temperature to remain low or become stuck at a certain temperature.

It is possible for the thermostat to get stuck at a certain position as it mechanically opens and shuts to regulate coolant flow. 

Hence, there would be an erratic reading from the thermostat to the ECM about the temperature of the coolant. 

Firstly, check the thermostat housing and the connecting wires for damages. If the connections are good to go, you might need to replace the thermostat. 

The thermostats are expensive and cost around $300 or more, depending on your Jeep model year.

Read Also: How to Troubleshoot & Fix P0420 Jeep DTC Code? (Ultimate Guide)

5. Look into the Water Pump and Radiator Functions

To ensure that the engine is properly cooled, the water pump moves coolant through the engine and radiator. 

If the water pump breaks down, there may be a reduction in coolant flow, leading to overheating and inaccurate engine coolant temperature readings.

On the other hand, your Jeep’s radiator is responsible for dissipating heat from the engine coolant and keeping it at the right temperature. 

The engine may overheat if the radiator becomes blocked, which can hinder the coolant flow.

You can start by flushing the radiator to remove debris or clogged specks of dirt from it. 

If the problem persists, you must replace the water pump itself, which may cost you somewhere between $700-$800, including part and labor charges.

Read Also: How to Troubleshoot & Fix P0522 Jeep DTC Code? (Detailed Guide)


You might want to take a look at these FAQs from the Jeep owners about their experience dealing with the P2181 code.

Can you drive a Jeep with P2181 Code?

Technically, you can drive your Jeep with a P2181 code, but not for a long time. Driving with this code might result in engine overheating issues, which can damage the engine in the long term. 

How much does it cost to fix the Jeep P2181 code?

The cost to fix the P2181 Jeep code depends upon the problem source. If the coolant is low or the ECT sensor needs replacement, you can cover it up for less than $100. But replacing the thermostat or water pump can charge you over $500.

What are the symptoms of a faulty coolant temperature sensor?

Engine overheating, poor fuel economy, decreased engine performance, an illuminated check engine light, and a constant temperature gauge can all be caused by a malfunctioning coolant temperature sensor. In extreme circumstances, it may result in the engine stalling or misfiring.


Lastly, resolving the P2181 code in a Jeep requires a careful examination of the engine cooling system to pinpoint the issue’s source. Not solving the code may directly harm your Jeep engine due to overheating.

Most often solving the issue involves replacing the ECT sensor or refilling the coolant, but it is recommended to seek professional help.

Read Also: How to Troubleshoot and Fix Jeep B2204-00 DTC Code?

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