How Long Does a Coolant Temperature Switch (Sensor) Last?

The coolant temperature switch (CTS) provides you with alerts when the engine temperature is rising or when it is overheating. It is also called the coolant temperature sensor, and it is an important part of keeping you safe and your vehicle running well.

Coolant from inside the cylinder heads and engine block absorbs heat from the cylinders while your vehicle is running. The CTS detects these changes in temperatures and alerts the powertrain control module (PCM). The message the sensor sends to the PCM affects the overall operation of the engine because much of the fuel, emissions, ignition, and drivetrain functions are handled by the PCM. Therefore, these functions are affected by the operating temperature of the engine.

If the PCM gets a cold reading from the CTS, the injector pulse width is increased to create a richer fuel mixture. This prevents hesitation while the engine is warming up. Once the engine is warm, the PCM reduces the mixture to make it leaner. The PCM cycles the cooling fan on and off to make sure the engine stays cool and to prevent it from overheating. The PCM cycles this by using information from the coolant temperature sensor.

The coolant temperature switch can go bad over time, whether it is due to wear and tear, or an electrical issue. At some point, your coolant temperature switch may need to be replaced by a professional mechanic.

Since the CTS can go bad, you should be aware of the symptoms it gives off before it completely fails.

Signs your coolant temperature switch needs to be replaced include:

  • Poor fuel economy
  • Black smoke coming from the exhaust pipe
  • Trouble starting your vehicle even after reaching normal operating temperature
  • Your vehicle fails an emissions test
  • You vehicle is constantly overheating
  • The temperature sensor is not consistent and behaves erratically
  • Check Engine Light comes on
  • Engine stalls or has a rough idle

The CTS is an important part of your vehicle, because without it, your engine will run poorly and overheat on a regular basis. Eventually, if left as is, the engine will go bad and the vehicle will become inoperable.


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Recent Coolant Temperature Switch (Sensor) Replacement reviews

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Collins

12 years of experience
488 reviews
Collins
12 years of experience
GMC Acadia V6-3.6L - Coolant Temperature Switch (Sensor) - Atlanta, Georgia
Collins was very professional, knowledgeable, and on time. He has a great personality and helped me understand what was going on with my car. I highly recommend Collins.
Buick LeSabre - Coolant Temperature Switch (Sensor) - Atlanta, Georgia
Collins was very knowledgeable about the service and patient with my questions He also found other problems and explained so that I could understand. I will use him for these fixes too. Clean, professional personality. He was also on-time showing up a little early which was good for my anxiety when its starts getting close to appointment time. Today is only day one after my service and I took one small trip later on late afternoon and it was a good trip.

Marco

29 years of experience
221 reviews
Marco
29 years of experience
Subaru Outback H4-2.5L - Coolant Temperature Switch (Sensor) - Perris, California
Excellent mechanic!!! Marco provided a expert professional service on my vehicle today; thank you kindly.
Land Rover Range Rover Sport - Coolant Temperature Switch (Sensor) - Upland, California
Marco came to my house trice - he called 30 minutes before - he was very knowledge and pleasant - and he fixed the problem very fast. His service was outstanding - the best mecanic I have ever had - I am very pleased and I will GREATLT recommend his services

Mathew

6 years of experience
54 reviews
Mathew
6 years of experience
Dodge Charger V6-3.6L - Coolant Temperature Switch (Sensor) - Philadelphia, Pennsylvania
Very friendly and professional, came early to work and walked me through what was completed and even given advise on preventative steps in the future. Would definitely recommend!

Diana

18 years of experience
90 reviews
Diana
18 years of experience
Volkswagen Tiguan L4-2.0L Turbo - Coolant Temperature Switch (Sensor) - Summit, New Jersey
Diana was very thorough and explained what she did, what she found and provided helpful insights. Came across as very knowledgable and trustworthy.

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