WOMS
P code powertrain Medium severity

P1474 Low Fan Control Primary Circuit Malfunction

The OBD2 code P1474 indicates a malfunction in the primary circuit of the low-speed cooling fan control system, which may affect the engine's cooling efficiency

Definition

The OBD2 code P1474 indicates a malfunction in the primary circuit of the low-speed cooling fan control system, which may affect the engine's cooling efficiency

Common causes

  • Faulty cooling fan relay
  • Damaged wiring or connectors in the fan circuit
  • Failed cooling fan motor
  • Malfunctioning engine control module (ECM)
  • Faulty temperature sensor
  • Blown fuse related to the cooling fan circuit
  • Poor ground connection for the fan circuit

Common misdiagnoses

  • Faulty cooling fan
  • Bad fan relay
  • Wiring issues or shorts in the fan circuit
  • Faulty engine control module (ECM)
  • Incorrect coolant temperature sensor readings
  • Air conditioning system issues
  • Faulty thermostat
  • Blocked or restricted cooling system
  • Low coolant levels
  • Faulty temperature control switch

Troubleshooting steps

  1. 1. Check the Vehicle's Service Manual

    Refer to the specific service manual for your vehicle to understand the wiring diagrams, component locations, and specifications related to the cooling fan system

  2. 2. Visual Inspection

    Inspect the wiring and connectors associated with the cooling fan and the fan control module for any signs of damage, corrosion, or loose connections

  3. 3. Check the fan itself for any physical damage or obstructions that may prevent it from operating

  4. 4. Test the Cooling Fan

    Manually activate the cooling fan by applying direct power to it to see if it operates. If it does not run, the fan may be faulty and needs replacement

  5. 5. If the fan operates when powered directly, the issue may lie in the control circuit

  6. 6. Check the Fan Relay

    Locate the cooling fan relay and test it for proper operation. You can swap it with a similar relay in the fuse box (if applicable) to see if that resolves the issue

  7. 7. Ensure that the relay is receiving the correct voltage and that the control signal from the engine control module (ECM) is present

  8. 8. Inspect the Cooling Fan Control Module

    If your vehicle has a separate cooling fan control module, check it for faults. This may involve testing the module for proper operation and ensuring it is receiving the correct signals from the ECM

  9. 9. Scan for Additional Codes

    Use an OBD-II scanner to check for any additional trouble codes that may provide more context or indicate related issues

  10. 10. Check the Engine Coolant Temperature Sensor

    The engine coolant temperature (ECT) sensor provides input to the ECM regarding the engine's temperature. If this sensor is faulty, it may not signal the fan to turn on when needed

  11. 11. Inspect the ECM

    If all other components check out, the issue may lie within the ECM itself. Ensure that the ECM is functioning properly and that it is programmed correctly for your vehicle

  12. 12. Clear Codes and Test Drive

    After performing repairs or replacements, clear the trouble codes using an OBD-II scanner and take the vehicle for a test drive to see if the code returns

  13. 13. Consult a Professional

    If you are unable to diagnose or resolve the issue after these steps, it may be best to consult a professional mechanic or technician who has experience with your specific vehicle make and model.Conclusion Always remember to take safety precautions when working on a vehicle, and if you're unsure about any step, it's best to seek professional assistance