Where is the Coolant Temperature Sensor located?

Location of the Coolant temperature sensor

My car has 200 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
Coolant temperature sensor is located at the upper radiator hose where it connects to the engine. Should be a green plug connector just to the left of the hose.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

There are two temperature sensors in some vehicles, one to send information from the engine system to the control unit and another from the control unit to the dashboard. The device follows the principle of dependence of potential difference in temperature.
The coolant temperature sensor, also known as the coolant temperature switch, is an engine management system sensor that is used to monitor the temperature of the engine`s coolant.

Higher idle speed. Increased fuel consumption. Poor starting behaviour.

The coolant temperature sensor is fastened to the intake manifold of an engine coolant and is often referred to as a negative temperature coefficient type of sensor.
On most modern cars, the cooling fan is controlled by the Engine Control Unit (ECU) which gets a signal from the coolant temperature sensor. If it`s not working, the fan won`t turn on when it needs to, which means the engine might overheat.
The ambient temperature sensor (switch) is located either behind the front grille or in the front bumper.
The Thermocouple As A Temperature Sensor. The Thermocouple is by far the most commonly used type of all the temperature sensor types. Thermocouples are popular due to its simplicity, ease of use and their speed of response to changes in temperature, due mainly to their small size.
P0115 Engine Coolant Temperature Circuit Malfunction Trouble, check the coolant level but it could be a bad coolant temperature switch that reports engine coolant temperature to the computer or its associated wiring.
P0115 is the OBD-II generic code that indicates when the engine control module (ECM) reads the ECT sensor input go below or above the sensors expected range of 0.14 to 4.91 V (-40°C to 140°C -40°F to 284°F).

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

No coolant in the reservoir. Seen low coolant message. I added 2 quarts of 50/50 coolant. Still getting the message. How much coolant doe it need?
ANSWER : Hi there. For the coolant light to go out, you would need to have the coolant between the low line and the full line for the light to go out. If the coolant is low and keeps on being low, then look for any signs of coolant leaks. You may have to use a coolant pressure tester to pressurize the reservoir to allow the leak to be found.

If you need further assistance with the coolant being low and the warning light being on, then seek out a professional, such as one from Your Mechanic, to help you.

Vehicle stall while driving. Crankshaft Position Sensor and Coolant Temperature sensor replaced.
ANSWER : Was the output of the crankshaft position sensor viewed on a scope? If not, the sensor might have been perfectly good. If you are working off of codes please note that the mere presence of a code is not enough to condemn any parts. Codes represent clues only, and sometimes lousy clues, and all parts that might be "referred" to in a code must be actually tested before any determination can be made. With regard to the check engine light, the codes that are now being reported, whether new or old, should be tracked down which means the individual components have to be tested using the appropriate test equipment. Occasionally codes will set and identify components that actually have absolutely nothing to do with causing the underlying fault. At this juncture, the best thing to do to get this resolved is request a check engine light diagnostic. The responding certified mechanic will PINPOINT the actual cause of the fault and get this resolved promptly. If you have further questions or concerns as you decide what to do, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you get the best possible results.

where is the coolant temperature sensor located 2002 mercury sable
ANSWER : Hi there. The coolant temperature sensor on most Ford (Mercury is a Ford product) V-6 engines is located on the intake manifold, front of the motor and next to the primary coolant hose. If you don’t have one currently, if you’re going to attempt this repair on your own, it would be a very smart idea to purchase a service and repair manual online for your vehicle. It’s very handy and will give you great tips on how to correctly complete this and many other repairs.

Where is the Coolant Temperature Sensor located?
ANSWER : Coolant temperature sensor is located at the upper radiator hose where it connects to the engine. Should be a green plug connector just to the left of the hose.

Car temperature keeps going up and coolant level drops.
ANSWER : Hi there. The milky engine oil is caused when the coolant from the cooling system gets into the engine oil. There are two ways that the coolant can mix with the oil on your vehicle. The first way is through the intake manifold as the gasket may crack causing the coolant to drain into the valley area making the coolant mix with the engine oil. However, the engine will not overheat quickly when this happens. The second way for the coolant to mix with the engine oil is through a burned head gasket. To verify that the head gasket is burned, get a block tester from your local parts store and set up the tool by putting the blue chemical in the tube and putting on the plunger on the end. Then remove the reservoir cap or radiator cap (take precautions of the coolant) and start the engine. Take the tool and place it over the inlet area to the reservoir or radiator. When steam starts to form in the area, use the plunger and suck in the steam into the tool. If there is any hydro carbons (raw unburnt fuel) in the cooling system, then the blue chemical will turn to a yellow or greenish color. If the color changes, the head gasket is burned and needs replaced. If the chemical does not change color, then the head gasket is good and there could be a leak on the intake gasket. I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose your engine overheating issue.

throttle position sensor can it affect coolant temperature?
ANSWER : The throttle position sensor will not have anything to do with the coolant temperature. The problem with the coolant temperature gauge you had may be due to the coolant change that was done or the system itself has a problem. You stated that the fluids got changed but did not mention if the coolant was changed specifically.

In this situation, either your thermostat got stuck momentarily or there was an air pocket. Once it cleared, the thermostat opened normally and the flow returned back in the cooling system. I would have the system checked to make sure the coolant is full and that everything functions correctly.

If you decide to get this fixed, consider YourMechanic, as a certified technician can diagnose your cooling system and make the necessary repairs. Good luck.

Bad idling after coolant temp sensor replacement
ANSWER : If you have a bad knock sensor, then the engine timing may be going too low and causing the low rough idle. If the scanner gives a code, then have it diagnosed and fixed. A vacuum leak will also cause the rough idle and I recommend having this checked for, located, and diagnosed.

Over heating coolant not siphoning back into coolant over flow tank
ANSWER : Hey there:

It’s common for many mechanics to make the mistake of mis-diagnosing the cause of an overheating situation; especially when they assume it’s a thermostat issue. The problem could be caused by a blockage in the coolant tubes running from the radiator to the overflow tank and back to the radiator. However, it also may be due to air trapped in the coolant lines. I think a good idea would be to contact a different ASE certified mechanic, such as one from YourMechanic, and have them complete a coolant flush, which should remove any blockages in the coolant tubes and may solve your problem.