Is P0128 a thermostat or sensor?
P0128 is a diagnostic trouble code that indicates an issue with the engine coolant temperature (ECT) system. Contrary to common belief, P0128 does not necessarily indicate a problem with the thermostat itself, but rather a problem with the ECT sensor or related components.
What is P0128?
The P0128 code is triggered when the engine coolant temperature does not reach a specified threshold within a certain amount of time after the engine is started. This could be due to a variety of issues, including a faulty ECT sensor, a stuck-open thermostat, or problems with the engine cooling system.
Is P0128 a Thermostat or Sensor Issue?
While a stuck-open thermostat can cause the P0128 code, it is more commonly an issue with the ECT sensor itself. The ECT sensor is responsible for monitoring the temperature of the engine coolant and relaying that information to the vehicle's computer. If the sensor is faulty or providing inaccurate readings, it can trigger the P0128 code.
Some common causes of a P0128 code include:
- Faulty ECT sensor
- Wiring issues with the ECT sensor
- Stuck-open thermostat
- Problems with the engine cooling system (e.g., low coolant level, leaks, etc.)
To determine the root cause of the P0128 code, it's important to perform a thorough diagnosis, which may include testing the ECT sensor, checking the thermostat, and inspecting the cooling system for any issues.
Diagnosing and Resolving P0128
If you receive a P0128 code, the first step is to use a diagnostic tool to read the code and any associated data. This can help identify the specific issue causing the code to be triggered. From there, you can proceed with further testing and troubleshooting to determine the root cause and make the necessary repairs.
In many cases, replacing the ECT sensor or addressing any issues with the cooling system will resolve the P0128 code. However, if the thermostat is stuck open, it may need to be replaced as well. It's important to follow the manufacturer's recommended diagnostic and repair procedures to ensure the issue is properly addressed.
What is the code for a bad thermostat?
While there is a small chance that there is an issue with the running temperature of your engine, by far the most common issue with trouble code P0128 is a faulty thermostat. The exact location of the thermostat and issues related to a damaged thermostat may vary depending on your vehicle.
How do I know if I need a new temperature sensor?
An engine with a faulty CTS will often consume more fuel than normal, as the engine's coolant temperature is improperly read. Given that this symptom will continuously pummel the owner's pocket once it appears, it should promptly spur a sensor check, and replacement if a faulty CTS is confirmed.
Can I still drive my car with a P0128 code?
Can I Still Drive with a P0128 Code? P0128 isn't the worst code out there, but you should still have a professional mechanic check your car ASAP. Doing so assures you that your vehicle is always operating at its best, while preventing any additional damage.
How do I know if my thermostat or temperature sensor is bad?
Symptoms of bad temperature sensor
- Erratic Readings. Sudden jumps or drops in temperature readings.
- Open Circuit: Display shows a very high or infinite temperature.
- Short Circuit: Display shows a very low or negative temperature.
- Drift:
- Noise or Interference:
- Physical Damage:
What happens if the coolant temp sensor is bad?
Faulty readings from the coolant temperature sensor can cause the engine to miscalculate the air-fuel mix in the engine. Any time the air-fuel mix ratio is not in proportion, and if the fuel mixture becomes too rich, the fuel will not be able to burn up inside the combustion chamber.
How do I know if my thermostat is faulty?
A bad thermostat can be detected when your AC or furnace is not turning on, your HVAC systems are not turning off, the thermostat not responding, your HVAC system is short-cycling, the room temperature not matching the temperature displayed on the thermostat, and the programmed setting resetting themselves.
How can I test if my thermostat is bad?
A bad thermostat can be detected when your AC or furnace is not turning on, your HVAC systems are not turning off, the thermostat not responding, your HVAC system is short-cycling, the room temperature not matching the temperature displayed on the thermostat, and the programmed setting resetting themselves.
Is coolant temperature sensor same as thermostat?
The coolant temperature sensor (CTS) can be found somewhere near the engine thermostat, which allows it to function optimally. The tip of the CTS is probably located right next to the engine coolant. The sensor works by measuring the temperature that's being given off by the thermostat and/or the coolant itself.
What is the difference between a temperature sensor and a temperature controller?
These sensors play a vital role in collecting temperature data, but they do not influence the temperature directly. Temperature controllers, on the other hand, are active devices that not only receive temperature information from sensors but also make decisions based on this data to control the system's temperature.
Is the code P0128 permanent?
Yes a low coolant level as well as a faulty thermostat can cause a p0128 code to set. On these later model vehicles when they set a code and the code is cleared it keeps a copy of the code stored in the background even tho the engine light is now off. This is referred to as a permanent code.
