Understanding the Thermostat Sensor: Its Importance and Replacement Guide

Thermostat sensor is an essential element for maintaining proper cooling operations. The small part functions to maintain steady engine operation. The sensor ensures that the engine operates within safety temperature ranges. 
Here we will look at what a thermostat sensor does and more about it.

What is a Thermostat Sensor?

The engine coolant temperature monitoring function belongs to the thermostat sensor device. It sends important information to the engine control unit. The data sent to ECU helps determine the essential decision-making process for cooling fan operation.
In order to maintain proper engine functioning you need to regulate its temperature correctly. Your vehicle operates efficiently and achieves maximum performance through use of the sensor-controlled temperature system.

 

How the Thermostat Sensor Works?

The thermostat sensor is usually found near the thermostat housing in your vehicle. It works like a thermistor. Its electrical resistance changes according to the detected temperature. The resistance decreases when the coolant temperature level increases.
When the engine temperature is cold the thermostat sensor instructs the ECU to blend extra fuel into the air mixture for engine heating. The sensor informs the ECU to activate the cooling fans once the engine temperature exceeds normal parameters. Engine overheating prevention occurs through this feature. It ultimately provides protection against damage.
Symptoms of a Failing Thermostat Sensor
The improper functioning of the thermostat sensor leads to multiple system malfunctions. Such problems create performance issues that also reduce fuel efficiency. Several indicators prove that your thermostat sensor requires replacement. These include:

• 1.Inconsistent Temperature Readings
  One of major indications of a faulty thermostat sensor is inaccurate reading displayed on your dashboard temperature gauge. The sensor has an issue when it displays hot readings at cold engine temperature.
• 2.Poor Fuel Economy
  An improper working thermostat sensor leads to decreased fuel efficiency in cars. A sensor that transmits incorrect signals to the ECU will cause the engine to consume an excessive amount of fuel. A faulty sensor will decrease your fuel efficiency as well as slow down your engine performance over time.
• 3.Cooling Fans Not Turning On
  If the sensor stops working, it might prevent the fans from turning on. This can cause the engine to overheat. If you notice that your cooling fans are not working properly, the thermostat sensor could be the reason.
• 4.Engine Overheating
  An inaccurate high temperature reading generated by the thermostat sensor will produce engine overheating. When the thermostat sensor sends persistent cool signals to the ECU then the cooling fans may not activate. Rising engine temperatures will occur because of this condition which leads to engine overheating.
• 5.Excessive Smoke from the Exhaust
  Your engine produces black exhaust smoke when the fuel mixture creates a malfunctioning. A faulty thermostat sensor can be the reason behind such issues. A faulty sensor that sends false readings will result in instable air-fuel mixture. Inadequate burning of the fuel will be leading to incomplete combustion and black smoke.
• 6.Starting Difficulties
  The failure of a thermostat sensor can lead to problems in starting your vehicle. It will also be affecting its running ability. The air-fuel mixture control mechanism in the ECU operates through precise temperature data supplies. The sensor performs this task most critically when cold weather conditions demand engine ignition.
• 7.Check Engine Light Activation
  Check engine light is an important thing on modern vehicles. It alerts their drivers when system malfunctions occur. The warning light can be activated when the thermostat sensor does not operate correctly. Your vehicle signals for you to investigate deeper into its current state through this light. 

Related Reading: 5 Common Causes of ECU Failure and Effective Prevention Strategies

How to Replace the Thermostat Sensor

If you have figured out that your thermostat sensor is faulty, you can replace it. Here is a simple step-by-step guide to help you with the replacement process:
Tools You Will Need
 

• Replacement thermostat sensor
• Safety equipment (gloves and safety glasses)
• Coolant collection container
• Flat screwdriver
• Socket wrench set
• Funnel
• Jack (if necessary)
• New coolant

Step-by-Step Replacement Procedure

Here are the steps you need to follow to replace thermostat sensor in your vehicle:
 

• 1)Safety First
  Start any automotive maintenance only after the engine completely cools down. Working with hot engine will cause painful burns with the risk of serious injuries.
• 2)Prepare the Vehicle
  The first step should be parking on a flat spot outdoors and waiting until your engine has adequately cooled down. Safety and easy replacement of the sensor are promoted by performing this step.
• 3)Drain the Coolant
  Place a drain pan under the radiator and drain about two to three quarts of coolant. This will lower the coolant level. It will also help you to prevent spills when you take out the thermostat sensor.
• 4)Locate the Thermostat Sensor
  The thermostat sensor positions itself right by the thermostat housing which resides on the engine block surface. Service manuals of your vehicle contain precise instructions about the thermostat sensor location.
• 5)Disconnect the Old Sensor
  You should disconnect both the electrical connector and wires from the thermostat sensor. To disassemble specific sensors, you need to detach their wire attachments with a flat screwdriver.
• 6)Remove the Old Sensor
  Use a socket wrench to gently unscrew the old thermostat sensor. Be ready for a little coolant to spill out.
• 7)Install the New Sensor
  Before putting in the new sensor, check if it needs a sealing washer or thread sealant. If it does, apply a thin layer of sealant. Then, install the new sensor and tighten it according to your vehicle's manual.
• 8)Reconnect the Electrical Connector
  Once the new sensor is securely in place, reconnect the electrical connector. Make sure it clicks into place to avoid any loose connections.
• 9)Refill the Coolant
  Use a funnel to refill the radiator with fresh coolant. If you saved the coolant, you drained earlier and it is still good, you can use that too.
• 10)Check for Leaks and Test
  Start the engine and let it run for a few minutes. Look around the thermostat sensor for any signs of coolant leaks. Also, check the temperature gauge with OBD2 Scanners to make sure it stays in the normal range.
• 11)Final Checks
  Perform this test following a brief driving session then inspect the coolant level before watching the temperature gauge. Regular checks using this method will verify system operations.

Final Thoughts 

Your vehicle depends on the thermostat sensor as an essential part of its cooling system operation. The sensor exists as a vital component that helps to preserve engine temperature and operational excellence. Proactive measures will help it to function properly with optimal efficiency. A failing sensor becomes detectable when a driver understands how the sensor functions combined with its clear indicator signals.
Regular maintenance and timely repairs will ensure the longevity and reliability of your vehicle.

FAQs
 

Can I replace the thermostat sensor myself?
Yes, you can replace the thermostat sensor if you have the right tools. Following the steps listed above can help you to complete the job effectively. 
How often should I check my thermostat sensor?
It is good practice to inspect your thermostat sensor periodically. This is especially if you notice any symptoms of malfunction. 
What happens if I ignore a faulty thermostat sensor?
Ignoring a faulty thermostat sensor can lead to serious engine issues. This will include overheating. It can ultimately cause extensive damage to engine components.