What you Need to know about Coolant Temperature Sensor?

What is a coolant temperature sensor?

A coolant temperature sensor (CTS), also known as coolant temperature switch, is an important part of your car. It transmits signals if the engine is overheating or for some reason, the system’s temperature is rising. This device works as a thermistor. When we say thermistor, it is a temperature sensitive resistor. This changes the resistance with the temperature. At a certain temperature, it will automatically turn on to help the engine cool down and assist in warming up. This ensures the engine to operate at the safe temperature to avoid trouble.

Symptoms of a Bad or Failing Coolant Temperature Sensor

These are a few symptoms to watch out for when you have a bad or failing coolant temperature switch. Laid down are the basic questions for you to consider.

1. Is your vehicle consuming more gasoline than before?

2. Are you having trouble starting your vehicle even if the engine is at a normal

3. Black smoke is coming out your car’s exhaust pipe.

4. Are you experiencing frequent overheating?

The more “Yes” you answer, the more chances that your coolant temperature sensor is defective and needs to be replaced; the sooner the better. If you are uncertain, it is time for a mechanic to check it to make sure everything is in good condition. You don’t want hassles, do you?

How to Test a Coolant Temperature Sensor | DIY

What if you are leaving far, far away and a mechanic is nowhere to find? I am being exaggerated here. But really, what if? I have some good news for you. You can check and replace your faulty coolant sensor on your own. Here’s how.

1. Locate your coolant sensor.

The location varies as per car brand and manufacturer. But in most cases, you can find it near the thermostat of the cooling system, or inside it.

2. Connect Digital Volt-Ohm Meter

There are two leads on this meter; the red and the black. First, connect the black lead to a solid grounding. Next, locate the terminal end of your cooling sensor then connect the red lead of the volt-ohm meter. It is important to set the digital reading to 20K range before turning the meter on. This is for the initial testing.

3. Check the readings

Start the vehicle and let the engine run for full two minutes. Once done, turn it off and run the resistance testing again. Because the engine is warmer, you should see that the resistance is lower.

4. Run your car’s engine again. While the engine is running, continually check ohm meter and see if there are more than 200 ohms in variance between a cold and warm engine. If there is no 200 ohms showing in difference, your CTS is a candidate for replacement.

As the saying goes, “Prevention is better than cure”. We don’t want to have serious problems, right? The amount that will cost you in replacing small but really important part of your car is nothing compare to the cost you will acquire if an accident occur.

On the side note, you can purchase used coolant temperature sensor in good condition in auto parts store or salvage yards if you want a tried and tested one.