The coolant temperature sensor is what informs the car’s computer what the engine’s running temperature is. This will then change to how the engine runs. Before the automated systems in cars was the sole purpose of the choke. Now, with this special sensor, the engine will adjust itself so that it operates smoothly even on the coldest days and does not overheat once the temperature goes up. Testing this coolant temperature sensor, and then changing it where needed, is a very easy process.
FIND THE COOLANT TEMPERATURE SENSOR
The coolant temperature sensor is found on the engine block under the hood. Pull the latch for the hood and open it, ensuring it is secure before letting go.
You will look for the sensor within the engine block itself, using a drop light if you require help to see it better. Look at the front of the engine block in the middle of the pulleys. You will notice a small terminal sticking out of the block with a wire lead coming out of it. This is your coolant temperature sensor.
USE YOUR DIGITAL VOLT-OHM METER
Testing the coolant temperature sensor is a very fast process. With the use of a digital volt-ohm meter you can easily know if the sensor is faulty or not. Connect the black lead of the digital ohm meter to a solid grounding. This could be any solid piece of metal. Next, connect the red lead to the terminal end of the coolant temperature sensor. Before turning the meter on, set the digital reading to the 20K range.
For the testing process you will be required to turn the engine on. Let the engine run for a full two minutes to allow the engine to get up to running temperature. While the engine is running you have to be continually checking the digital ohm meter. You are looking for readings that are more than 200 ohms in variance between a cold and warm engine. If you do not see anything that is more than 200 ohms in difference, the coolant temperature sensor is defective and will have to be changed.
CHECK WITH COLD SENSOR
If you have a new sensor on hand and want to check it, you can carry out this easy test. Connect the black lead of the meter to the body of the cold sensor and the red to the terminal. You should have a reading of approximately 2000 ohms. Check too the warm sensor in your engine. You should notice a much lower reading on the digital meter. If not, then it is not working normally.
CHANGE DEFECTIVE COOLANT TEMPERATURE SENSOR
Changing the coolant temperature sensor is an easy process that anyone can do at home with some basic mechanic’s tools. Take out the lead coming from the terminal and loosen the sensor with a socket or wrench. Change with a new one and get back on the road in no time.