The engine’s performance is largely based on temperature measurements performed by the engine control module (ECM), also known as the vehicle’s computer. As the temperature of the engine increases, the resistance decreases which means the voltage drops. The computer receives this signal and converts it to a temperature value.
For example, when the engine is cold, it needs more fuel to start effectively. On the opposite end, when the engine is warm, it needs less fuel. The cylinder head temperature sensor monitors these temperatures and reports back to the ECM so it can adjust the temperature as needed.
The cylinder head temperature sensor can read from -40 degrees Fahrenheit to 260 degrees Fahrenheit. Furthermore, it consists of two sensors, one that monitors the high temperature and one that monitors the low temperatures. If the cylinder head temperature sensor is not providing the correct readings, the engine can have a variety of issues such as stalling, long cranking times, and hesitation while accelerating.
If you suspect there is an issue with the cylinder head temperature sensor, a professional from YourMechanic can read the sensor’s resistance. Furthermore, they will then compare the resistance to the temperature laser reading to ensure they match up. If there is a discrepancy between the readings, it could be a wiring issue or the sensor has gone bad. The cylinder head temperature sensor may need to be replaced or the wiring may need to be redone.
Since the cylinder head temperature sensor can go bad over time, or the wiring becomes bad, there are a few symptoms you should be aware of that indicate it is time for a replacement.
Signs that indicate you need a cylinder head temperature sensor replacement include:
- You have trouble accelerating while driving your vehicle
- The engine stalls when you start it cold
- The idle speed stays low when the engine is cold
- There is a long cranking time when you start your vehicle
- Your vehicle hesitates when you accelerate
Without a proper working sensor, your vehicle may not work right so this repair should be completed as soon as you notice the problem.
This article originally appeared on YourMechanic.com as How Long Does a Cylinder Head Temperature Sensor Last? and was authored by Valerie Johnston.