Fan Speed Sensor Circuit
The engine control module detected a problem with the cooling fan speed sensor circuit, which monitors how fast the cooling fan is spinning. This code means the sensor signal is abnormal, missing, or out of range, preventing proper cooling fan speed regulation.
What You Might Notice
- Check Engine Light illuminated
- Engine running hotter than normal or overheating
- Cooling fan not operating at correct speed
- Reduced cooling fan performance
- Potential temperature gauge reading higher than normal
Most Common Causes
- 1
Faulty cooling fan speed sensor
The sensor that reads cooling fan RPM has failed or become unreliable, sending incorrect or no signal to the PCM.
- 2
Open circuit or loose connection in sensor harness
The wiring harness to the cooling fan speed sensor is disconnected, corroded, or has a broken wire preventing signal transmission.
- 3
Faulty cooling fan or fan clutch
The electric cooling fan or mechanical fan clutch is not functioning properly, causing abnormal speed readings at the sensor.
- 4
Faulty PCM/ECM
The engine control module itself may have a defect in the circuit that processes the cooling fan sensor signal.
How to Diagnose It
- 1
Check Faulty cooling fan speed sensor — The sensor that reads cooling fan RPM has failed or become unreliable, sending incorrect or no signal to the PCM.
- 2
Check Open circuit or loose connection in sensor harness — The wiring harness to the cooling fan speed sensor is disconnected, corroded, or has a broken wire preventing signal transmission.
- 3
Check Faulty cooling fan or fan clutch — The electric cooling fan or mechanical fan clutch is not functioning properly, causing abnormal speed readings at the sensor.
- 4
Check Faulty PCM/ECM — The engine control module itself may have a defect in the circuit that processes the cooling fan sensor signal.
How to Fix It
- 1
Inspect and repair cooling fan sensor harness
Check the wiring harness connected to the cooling fan speed sensor for loose connections, corrosion, or damaged wires. Reconnect or repair as needed.
- 2
Replace cooling fan speed sensor
Remove the faulty sensor and install a new one to restore proper cooling fan speed signal transmission to the PCM.
- 3
Inspect and replace cooling fan or fan clutch
Test the cooling fan operation; if it is not spinning at the correct speed or fails to operate, replace the electric fan motor or mechanical fan clutch.
- 4
Check accessory belt condition
Inspect the serpentine belt for cracks, fraying, or damage that could affect cooling fan operation. Replace if worn.
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