What is fan control relay?
A cooling fan relay is used on vehicles that have an electrical fan to cool the engine. The function of the cooling fan relay is to convert a low voltage signal from either the electronic control module (ECM) or a thermostatically controlled sensor.
What does the relay on a cooling fan do?
The typical electric cooling fan circuit includes a temperature sensor, a relay, a control module and the fan motor. The relay is the component that fails most often; so be sure to test the relay as well as its power supply and ground connections.
How does the p0480 cooling fan relay work?
The PCM (powertrain control module) senses the increase in engine temperature through the CTS (coolant temperature sensor) located near the thermostat. When the temperature reaches about 223-degrees F (value depends on make/model/engine), the PCM will command the cooling fan relay to turn on the fan.
How does the PCM control the cooling fan?
The PCM controls the cooling fan by grounding the cooling fan control circuit which turns ON the cooling fan relay. The cooling fan relay will be commanded ON when the following conditions are met: – The engine coolant temperature reaches 106°C (223°F) or more. – The A/C clutch requested. – The vehicle speed is less than 38 MPH.
What causes a DTC on a fan relay?
Potential Causes. The causes for this DTC may include: Faulty fan control relay 2. Fan control relay harness is open or shorted. Circuit electrical connections poor. Faulty cooling fan 2. Faulty coolant temperature sensor. Fan cooling fan harness is open or shorted.
What is the function of a radiator fan relay?
The function of the cooling fan relay is to convert a low voltage signal from either the electronic control module (ECM) or a thermostatically controlled sensor. The cooling fan relay takes the low voltage signal and internally switches the relay “on” to allow battery voltage to be supplied to the radiator cooling fan.
Where is the coolant fan relay located?
The cooling fan relay is normally located in either the underhood fuse and relay center or mounted to the electric fan assembly behind the radiator. To replace the cooling fan relay, there are two methods that we will cover for the positions mentioned above.
Where is the fan relay?
Fan relay is located one of two places — inside the fuse box, or on the front radiator crossmember, down low, visible from underneath the vehicle, usually on driver’s side.