AutoCodes.com | All About OBDII Engine Codes
AutoCodes - Jeep - P0128 Jeep

P0128 Jeep Code - Thermostat Rationality

- Code Popularity: 91,441 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 2/3
Table of contents
Share on Facebook   Share on Twitter   Share on Linkedin

What are the Possible Causes of the DTC P0128 Jeep?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Leaking or stuck open thermostat
  • Low engine coolant level
  • Insufficient warm up time
  • Faulty engine coolant temperature sensor
  • Engine coolant temperature sensor harness is open or shorted
  • Engine coolant temperature sensor circuit poor electrical connection
⚠ Does your Jeep have Safety Recalls? → Check here

How to Fix the DTC P0128 Jeep?

Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

Code Tech Notes

If cooling system is not leaking and the fluid level is OK, replacing the thermostat usually takes care of the problem.

Search for P0128 Jeep Questions and Answers: Search here →

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0128 Jeep code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

When is the Code Detected?

Coolant temperature does not reach predicted engine coolant temperature within specific time

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

Code P0128 Jeep Description

Indicates that the thermostat monitor has not achieved the required engine operating temperature within a specified amount of time after starting the engine.

OBDII Code P0128 Jeep - Thermostat Rationality - AutoCodes.com
P0128 Jeep Code - Thermostat Rationality

Need More Information on the Code?

Need more information on how to fix the P0128 Jeep code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0128 Jeep code diagnosed by a professional: Find a repair shop in your area

Code P0128 Jeep comments

Help us improve AutoCodes.com. Leave a comment below or tell us if the information above helps you fix the code. What are the symptoms on your vehicle for the P0128 Jeep code? Have you replaced any parts?
Any information is appreciated. Thanks