How to Detect Temperature Switch Failure

The sensor, which is called the temperature switch or the heat switch, is a part that measures the temperature of the engine and transmits it to the vehicle’s brain, which costs money to replace it. It is made of a semiconductor material.

The resistance value of the semiconductor material changes with the effect of heat. This value is sent to the vehicle’s brain. The vehicle’s brain makes fuel and other adjustments according to the engine temperature. If the temperature switch is broken, complaints such as excessive fuel consumption, chip fuel consumption, late starting, black smoke from the exhaust, stopping can be seen as these adjustments cannot be made.

How to Detect Temperature Switch Failure

The working principle of the temperature switch is as follows:

This device works on the principle of dependence of potential difference in temperature. As the temperature of the motor changes, the potential difference output of the device also changes and this can be measured by the motor control unit. So, in principle, the temperature sensor is a thermistor.

The temperature of a thermistor affects its resistance inversely. As the temperature rises, the resistance of the vehicle’s coolant decreases, which reduces the potential difference output. This voltage output is sent to the vehicle’s electronic control unit, which continuously measures the resistance on the vehicle’s coolant. By continuously monitoring the coolant resistance (and voltage output), the temperature sensor sends temperature information to the vehicle’s engine control unit.

How to detect temperature switch failure

If you think that there are some problems in your vehicle and it is caused by a malfunction of the temperature sensor, the first place you should look is the engine malfunction lamp. If the temperature switch is broken, the engine fault lamp lights up continuously.

There are other reasons why the check engine light stays on. In order to understand that the problem may be caused by the temperature sensor, it is necessary to look at the temperature indicator.

In a normal traffic, the temperature gauge is around 85-90. If you have felt an abnormality in the movement of the needle recently, if the needle is moving too low while driving at a normal speed, the temperature sensor may be broken.

There are other indications that the temperature switch is faulty. For example, when the engine is too hot, the car may stop by itself because the sensor does not detect it. Such stalling at high speeds can also lead to an accident.

Other symptoms are:

Black smoke coming out of the exhaust: The brain cannot adjust the fuel well due to the fault of this sensor. Black smoke coming out of the exhaust is a sign of this.

Increased fuel consumption: Drivers cannot detect this easily. Because the fuel consumption may vary according to the way the vehicle is used. However, if you have detected that your vehicle has been consuming too much fuel lately, consider the possibility that the temperature sensor or one of the other sensors may be defective. If you’re using more fuel on the same road, your car’s computer may be getting incorrect data from the sensors.

Experiencing vehicle starting problems: If the engine temperature cannot be measured, many problems can occur. Although it reaches the required temperature, you may not be able to start your vehicle.

Engine overheating: If you notice that the engine is overheating even though the temperature gauge shows normal, it is most likely that the temperature sensor has failed.

Where is the temp switch on the engine?

The temperature sensor is located on or near the water outlet pipe on the side of the engine cylinder head.

Leave a Comment