Skip the auto shop - Our mechanics make house calls

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

coolant temperature switch

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.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

How Long Does a Throttle Return Spring Last?
Not all vehicles on the road feature an electronic throttle control (ETC), which is also called drive-by-wire. For vehicles that don't offer this system, they have a throttle cable instead that...
How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...
The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Shutterstock.com Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....


Related questions

Q: My battery is being drained by the constant running of the coolant fan

This is a sign of a failing coolant fan switch. As you may know, the coolant fan switch helps to maintain the proper coolant temperature by turning on and off at specific temperature thresholds based upon inputs from the coolant...

Q: Heater blower

If the blower motor does not respond to on and off commands at the switch, generally the switch is faulty. The turn signal issue is probably not related to the problem with the blower. If you hear the flashing unit...

Q: A fuse blows when power seats are used

The power seat motors on your 2004 Kia Amanti have only one fuse, and it is a 30 amp fuse. If you replace this fuse, and it blows when you try and operate the seat then there is a problem...