Where Is the Temperature Sensor on My Car? (Explained!)

Every car has a temperature sensor that monitors its operating temperature. Thus, it alerts the system and takes immediate action when it sees a potential problem. With such importance, this sensor needs to be in the right place to measure the temperature. Thus, you may wonder:

Where is the temperature sensor on my car? Most cars have two sensors. The external temperature sensor you can find near the cylinder head or block or on the thermostat case. An extra sensor is usually in the engine or the radiator. This one is internal, and you may or may not find it. 

In general, the external temperature sensor gives accurate information. However, it can be influenced by many factors, such as the heat of the road where it runs. For this reason, anyone who drives in sweltering conditions can reach a few degrees higher than the actual temperature of the car.

In this article, we’ll have a thorough discussion on the car’s temperature sensors. This way, you’ll know where to find them and understand a little bit more about how they work. It will also give a sense of how your car’s temperature monitoring system works and how you can correctly interpret them.

Without further ado, let’s get into it!

Where Is the Temperature Sensor on My Car

Where Is a Car’s External Thermometer?

As I mentioned earlier, a car’s external thermometer or temperature sensor is near the cylinder head or block. Or, it can also be near the thermostat case. 

In general, you can find it under the front of your car’s hood or near the bottom of your car. Since this thermometer plays a vital role in your car’s system, you can be sure that it’s accurate and reliable.

Now, the only thing is that since it’s an external temperature, the readings it gives might be affected by many factors.

For instance, if you’re driving on the road under a scorching temperature, you may find the reading a few degrees higher than the correct reading.

Don’t worry, though, as it’s still reliable information. Further, it still works better as it will help you be aware and be extra careful when you’re driving in such conditions.

How Many Temperature Sensors Are in a Car?

As I mentioned earlier, you’ll usually find two temperature sensors in a car. One of the two is external, which measures the air temperature. The other one is internal, and it’s usually located near the radiator.

On other vehicles, two temperature sensors work in complement to each other. For instance, one of the sensors sends information from the engine towards the control unit. The second sensor works by sending the information sent by the other to the driver in the dashboard.

These temperature sensors allow the control system to detect engine overheating or an unexpected temperature increase. It is generally positioned adjacent to or within the thermostat, according to the automotive company.

These sensors also work on the concept of thermal potential difference dependency—the potential difference in the production of the car changes when the temperature of the engine changes. The car’s control system may monitor such an issue.

How Does Temperature Sensor Work in Car?

As I mentioned earlier, the temperature sensors work in a car to complement each other and provide information to you and your engine system. As a result, you’ll stay informed of potential problems, and the engine can take immediate action on minor issues.

Here’s how the temperature sensors work in your car:

  1. The temperature sensors operate by detecting the heat emitted by the thermometer and the antifreeze or the cooling system.
  2. After detecting the temperature, the sensor will relay the information to the onboard control system. 
  3. The control system of your car will take this detail to decide whether it will continue running as it is or change some of its functions. In simple terms, it adjusts its work according to the temperature reading given by the sensor.
  4. Once the control system gets the sensor’s reading, it may or may not start the cooling fan or stop it from running.
  5. In some cases, the control system may force the engine to use a richer fuel mixture. Or, it can also make the engine open the exhaust gas to improve the current airflow.

Like all other auto parts, the temperature sensor is also prone to damage and eventual wearing due to use over time. 

What to do when the temperature sensor fails?

Such a failure may cause overheating and even other issues for your car. For this reason, you may also want to know how to detect such when it happens.

You may do a quick assessment to determine whether the engine sensor has developed any fractures or splits, provided you know its position and appearance.

Although a quick assessment works a long way, it won’t assist you in finding every possible issue because inevitable sensor failures aren’t visible.

If your temperature sensor isn’t operating correctly, it will send a message to the system, causing your Check Engine light to activate.

Thus, if your car’s Check Engine light comes on, take your automobile to a competent mechanic straight away.

When should you replace the temperature sensor?

Like all other parts, the temperature sensor will wear over time and will need replacement. Thus, you may consider replacing your temperature sensor after considering the following:

Engine damage

Sensor maintenance is usually advised if the engine experiences any stress or damage. The reason is that you don’t want to risk driving the car with a malfunctioning one.

For this reason, it would be best to replace your temperature sensor if your car underwent inevitable damage, especially the cooling system.

Wear over time

After a certain period, even normal wear and tear might degrade the temperature sensor. Thus, you’ll want to replace your temperature system after several years to ensure that you get accurate temperature readings at all times.

A competent vehicle mechanic can always change your car’s temperature sensor. This component of regular maintenance may save you a lot of time and aggravation in the longer term.


In a nutshell, you can always find one or two temperature sensors in your car. The common one is the external temperature sensor, and it’s usually located outside your car, in the front, or under the hood.

The temperature sensor works by relaying the accurate temperature to prevent overheating so the engine system can do certain functions. Thus, your sensor needs to be in good condition at all times.

Like other parts, you’ll find the need to replace this part at certain times to make sure you get the best reading. Also, it will help you prevent other issues and save you a lot of expenses as you go on.

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Image credits – Canva

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My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more