how to diagnose P0174 code in Ford Explorer Sixth Generation (2020-present)

Solution

1. Preparation

• Tools Required: OBD-II scanner, vacuum gauge, fuel pressure gauge, MAF cleaner, multimeter, smoke machine.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Start the engine and listen for hissing sounds indicating vacuum leaks.
  2. Use a smoke machine to introduce smoke around intake components to visualize leaks.
  3. Replace any damaged hoses or gaskets found during inspection.

3. Test and Clean MAF Sensor

• Sub-steps:
  1. Disconnect the electrical connector from the MAF sensor.
  2. Remove the sensor from the air intake duct.
  3. Clean the sensor using MAF cleaner; ensure no residue remains.
  4. Reinstall the sensor and reconnect the electrical connector.

4. Check Fuel System

• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position without starting the engine; check the pressure reading.
  3. Compare the reading with manufacturer specifications; replace the fuel pump if it is below specifications.

5. Inspect Fuel Injectors

• Sub-steps:
  1. Remove the engine cover to access the fuel injectors.
  2. Check for any visible leaks or clogging.
  3. Replace any faulty injectors with new ones.

6. Verify Coolant Temperature Sensor Operation

• Sub-steps:
  1. Disconnect the coolant temperature sensor harness.
  2. Use a multimeter to test the resistance and compare it to specification.
  3. Replace the sensor if it is out of spec.