How does the radiator fan control work in a car?
There are often two different systems in different car models. Either your fan control is integrated into the engine control unit, or you have a separate fan control module. In both cases, the control units use a temperature sensor to know when to start the radiator fan.
How does the fan control module work?
It is a simple system as cooling fans go. The ECT sensor tell the PCM the temperature, at 209 degrees the PCM sends a pulsed power signal to the fan control module. That signal keeps getting faster as the temperature rises. The control module gets that signal and uses larger power transistors to pass the pulsed signal to the fan.
What does an engine coolant temperature sensor do?
The engine coolant temperature sensor’s job is to measure the coolant temperature for the engine control module. With this information, the engine control module adjusts the air-fuel mixture depending on the temperature.
How does the ECT sensor work on a fan?
It is a simple system as cooling fans go. The ECT sensor tell the PCM the temperature, at 209 degrees the PCM sends a pulsed power signal to the fan control module. That signal keeps getting faster as the temperature rises.
Does coolant temp sensor control fans?
As the control system receives the temperature from the CTS, it may trigger the cooling fan to either shut off or turn on. Additionally, it may signal the need for a richer fuel mixture or open the exhaust gas recirculation.
What tells the cooling fan to come on?
Fan Trigger The engine temperature should trigger the fan to turn on. It will also turn the fan off once the engine has cooled to under 200 degrees. You may have heard of a part called the radiator fan switch or temperature fan switch. This is linked to a thermostat and works much like your home's HVAC system.
Where is the cooling fan sensor located?
In most cars, the primary ECT sensor (ECT sensor 1) is installed near the thermostat in the cylinder head or block or on the thermostat housing. A second coolant temperature sensor could be installed in another part of the engine, or in the radiator.
What controls the electric radiator fan?
The PCM controls fan operation; it uses the signal from the ECT or engine coolant temperature sensor. This sensor senses the temperature of the engine's coolant and sends a variable voltage signal to the PCM. The PCM operates the fan motor through the engine's cooling fan relay.
Why are my radiator fans not kicking on?
The most common reasons a radiator fan is not working are luckily due to a blown fuse, bad relay, or a broken wire. It can also be caused by a faulty coolant temp sensor, low coolant level or the fan itself can be damaged.
How do you test a radiator fan relay?
4:309:13How to Test Cooling Fan Relays - Low and High Speed - YouTubeYouTubeStart of suggested clipEnd of suggested clipIf you want to test grab this other one the cooling fan relays that we have here starter relaysMoreIf you want to test grab this other one the cooling fan relays that we have here starter relays relays for actual you can hear it click well them. You hear that.
How do you know if your coolant sensor is bad?
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.
What are the symptoms of a faulty temperature sensor?
7 Symptoms of a Bad Coolant Temp Sensor & Cost to FixCheck Engine Light.Engine Overheating.Poor Fuel Economy.Poor Engine Performance.Broken Water Pump.Control of Cooling Fan.Black Smoke From Exhaust Pipe.
Is temperature sensor and coolant sensor the same?
There is no difference in the way those terms are used today. Technically, a sending unit has two or three wires, a power connection, a ground and an output wire that sends a signal, either a current or a voltage. A sensor, on the other hand, has one or two wires, a powered wire and a ground.
Does the ECM control the cooling fan?
Make sure the A/C is turned off, because you don't want the fans coming on as a result of high side pressure in the A/C system. Electric fans generally are controlled by a relay, which in turn is controlled by the Engine Control Module (ECM).
Where is the radiator fan control module?
The cooling fan control module in your vehicle is located at the front left of the engine compartment next to the radiator.
How are electrical cooling fans controlled?
The fans are controlled either with a thermostatic switch or by the engine computer, and they turn on when the temperature of the coolant goes above a set point. They turn back off when the temperature drops below that point. Rear-wheel drive cars with longitudinal engines usually have engine-driven cooling fans.
How are electrical cooling fans controlled?
The fans are controlled either with a thermostatic switch or by the engine computer, and they turn on when the temperature of the coolant goes above a set point. They turn back off when the temperature drops below that point. Rear-wheel drive cars with longitudinal engines usually have engine-driven cooling fans.
What controls the electric fans on a vehicle?
Electric fans generally are controlled by a relay, which in turn is controlled by the Engine Control Module (ECM).
How does the cooling fan work?
The primary function of a radiator cooling fan is to take away excessive heat absorbed from the engine. The coolant absorbs the heat and goes into the radiator where the heat is blown away. The system is functional when the engine is stationary, where air can't move through the grille.
What are the symptoms of a faulty cooling fan switch?
Common signs include engine overheating, the Check Engine Light coming on, and a broken or shorter signal wire.
How to check if radiator fan sensor is working?
You need to check your repair manual of which temperature sensor controls the radiator fan and then resistance-measure the sensor with a multimeter to ensure it is functional.
Why do we use radiator fans?
When you are driving fast, the wind passes through the radiator to cool the coolant down without issues, but when you are driving slow, no wind is pushed through the radiator. This is why we use a radiator fan.
Why is my radiator fan not coming on?
Because the radiator fan is often drawing so much power, there is often a relay that is powering the coolant fan. Of course, this relay can get damaged, which will cause the radiator fan to not coming on.
How to test radiator fan?
You can test the electrical radiator fans by taking a wire from the car battery, unplug the radiator fan connector, and put 12v+ and ground into the connector. This is the fastest and easiest way to test your radiator fans.
Why does my radiator fan control module fail?
This control module is often installed in the engine bay, exposed to heat and dust. This can make the control module fail after a while because of corrosion.
Why won't my radiator fan start?
You probably already know the purpose of the radiator and the cooling system in your car. When you are driving fast , the wind is passing through the radiator to cool the coolant down without issues , but when you are driving slow , there is no wind pushed through the radiator.
What is the fuse size of a fan?
The fan itself often uses a big fuse of around 50A, while there might also be a separate small fuse to the fan control module. Remember that if the fan fuse is blown – there might be a problem with the wirings or the radiator fan.
Where is the coolant temperature sensor located?
The engine coolant temperature sensor is usually located on the engine block or cylinder head. It is often installed on a plastic hose on the coolant’s inlet. Different brands and car manufacturers have different ways of placing the coolant temperature sensor depending on the car design. Some vehicles may have more than one temperature sensor, ...
What is a Engine Coolant Temperature Sensor?
The principle working of this sensor involves the use of an electrical resistance that measures the temperature of the coolant. These measurements produce essential data for the engine system of your vehicle.
How to tell if coolant sensor is working?
One of the first signs of all coolant temperature sensor symptoms you will probably notice is that the check engine light will show up on your dashboard.
Why won't my electric cooling fan come on?
Electrical Cooling Fans not coming on. Some cars use the engine coolant temperature sensor to control the electric cooling fans. You have two separate temperature sensors for the fans, dashboard gauge, and engine management in most cars. However, if your car has a single sensor, a bad engine coolant temperature sensor may result in your fans won’t ...
How to check a coolant sensor?
How to Diagnose a Faulty Engine Coolant Temperature Sensor? 1 Connect an OBD2 Scanner and look for related trouble codes. Check the live data to see the temperature from the sensor. If it is way off the range, check the wirings, and replace the sensor. 2 Locate the coolant temperature sensor in your vehicle by referring to the service manual. 3 Find the coolant temperature sensor and remove the connector plugs. 4 If you have two pins on the coolant temperature sensor, you can try ohm measure between these two pins. 5 Check your repair manual for the correct ohm-value at a given temperature. 6 If the value is wrong – replace the sensor. 7 If it seems fine, check the wirings and connectors between the coolant temperature sensor and the engine control module.
How much does it cost to replace a coolant temperature sensor?
The average coolant temperature sensor replacement cost is between $50 to $250, depending on the car model and labor costs. A coolant temperature sensor costs 30$ to 100$, and the labor costs 20$ to 150$.
Why does my fan not turn on?
If the fan receives a false signal , the fan might not turn on, causing the engine to overheat. Some vehicles have a separate coolant temperature sensor for the fan, but many cars use the same sensor.
How does an ECT sensor work?
It is a simple system as cooling fans go. The ECT sensor tell the PCM the temperature, at 209 degrees the PCM sends a pulsed power signal to the fan control module. That signal keeps getting faster as the temperature rises. The control module gets that signal and uses larger power transistors to pass the pulsed signal to the fan.
Does a radiator fan work when the heat sensor is unplugged?
Radiator fan only works when temperature sensor unplugged. Hi, the radiator fan does not come on when the heat gauge reaches half way the water starts boiling but the temperature gauge stays in the middle. I was told that it was a faulty temperature sensor which I replaced. The fan still inst working, however if I unplug the temperature sensor ...
