P0128 P0128 Coolant Temperature Below Thermostat Regulation
What P0128 means for you
Both sources align on a low severity.
Symptoms
- The check engine light is illuminated.
- The vehicle may experience delays in reaching optimal operating temperature.
- Engine temperature may rise excessively during highway driving.
- The temperature gauge may show lower readings than expected.
- The heating system may not function properly.
- Fuel efficiency may decrease.
- The vehicle might fail an emissions test if applicable.
- In rare instances, drivers may not notice any significant issues.
Common causes
- A malfunctioning coolant temperature sensor.
- The cooling fan may be continuously running.
- An issue with the intake air temperature sensor.
- A thermostat that is either defective or stuck in the open position, whether electronically controlled or traditional.
- The engine cooling system must achieve a critical temperature, usually between 160-170 degrees, within about 15 minutes of starting the engine. In very cold weather, the coolant must increase by over 70 degrees from its starting temperature. Failure to reach or maintain this temperature will prompt the PCM to trigger code P0128.
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Send your ECUWhat this code means
Error code P0128 indicates that the coolant temperature is below the threshold that the thermostat is designed to regulate. This condition can lead to various issues, including poor fuel economy and increased emissions, and should be addressed promptly to ensure optimal vehicle performance.
Frequently asked questions
While it is possible to drive with a P0128 code, it is advisable to have the issue checked by a professional to prevent potential damage.
The repair cost for a P0128 code can vary, typically ranging from $100 to $300, depending on the specific issue and labor costs.
Ignoring a P0128 code can lead to reduced fuel efficiency, increased emissions, and potential long-term damage to the engine.
