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Friday: 7am – 5pm

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How to Tell if You Have a Faulty Coolant Temperature Sensor

by | Jan 22, 2015 | Car Care Tips, General Car Maintenance, Vehicle Safety Inspections

auto-repair-5The coolant temperature sensor in your vehicle is an important device. It enables the control unit to give alerts if the engine is overheating. It will also alert you for if the temperature within the system is rising for some reason. If the vehicle overheats continuously, make sure to bring it in so we can inspect it. This way we can look for what might be causing the issue. By noticing an issue early on, you can help prevent more time, money, and stress in the long run. A vehicle that overheats constantly can lead to issues with the radiator if it is ignored. If there is a dashboard light that illuminates, it can also indicate an issue. It is important to remember if the light starts to blink, to turn the vehicle off as soon as you can.

What the Function of the Temperature Sensor is

The temperature sensor is able to sense when the vehicle is starting to overheat. This is important because you will want to keep the vehicle from overheating. As the temperature of the engine changes, the potential difference output of the device also changes, and the engine’s control unit can measure this. The temperature sensor will measure its resistance in an inverse proportion. As the temperature rises, the resistance of the car’s coolant drops and this in turn decreases the potential difference output. This voltage output is sent to the electronic control unit of the vehicle, which constantly measures the resistance across the car’s coolant. By this continuous monitoring of coolant resistance and the voltage output, the coolant temperature sensor sends temperature information to the vehicle’s engine control unit.

Where the Coolant Temperature Sensor is Located

Different vehicle manufacturers install the coolant temperature sensor differently. However, it is usually in close proximity of the thermostat of the cooling system, or inside it. There may be 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. However, some vehicles dispense with the need for two temperature sensors by using just one sensor to do both tasks. If there are two sensors, one of them is the coolant temperature sensor while the other is more correctly called the coolant temperature sending unit. This sends information from the control unit to the dashboard of the vehicle.

Symptoms of a Bad Coolant Temperature Sensor

If your vehicle starts to use a lot more gasoline than usual, or black smoke is starting to come from the exhaust pipe, these are indicators that the coolant temperature sensor in your vehicle could be defective, and needs to be replaced. If you start having trouble starting your vehicle after it has reached its normal operating temperature, this is usually a very good sign that you need to have the coolant temperature sensor checked. Another sign of your coolant temperature sensor not functioning properly is if your engine is overheating frequently. This can possibly happen when the coolant is leaking, causing the temperature sensor to behave erratically. In many vehicles, a faulty coolant temperature system will trigger a check engine light or service engine light on the dashboard of the vehicle. Also make sure to bring your vehicle in, so we can inspect it for you.