Does the Coolant Temperature Sensor Control the Radiator Cooling Fan?
Most late model vehicles on the road today feature electric condenser/radiator cooling fans. These fans are controlled by the ECU. The ECU relies on readings from the coolant temperature sensor to turn on/off the radiator cooling fan. Although the coolant temperature sensor does not directly control the radiator cooling fan, a faulty coolant temperature sensor can impede operation of the radiator cooling fan because it is not receiving the necessary signal from ECU to operate.
The best way to confirm if the coolant temperature sensor is faulty or if the radiator cooling fan is faulty is to use a diagnostic tool to identify fault codes that triggered the engine check light. It can be difficult to identify the cause of failure because signs of failure are nearly identical for both the coolant temperature sensor and radiator cooling fan. It is possible to test coolant temperature sensor voltage readings, however some vehicles may have multiple coolant temperature sensors. It is also important to assess the radiator cooling fan for damage and cease operation of the vehicle to prevent risk of overheating the engine if the radiator cooling fan is inoperable.