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, basic hand tools, multimeter, MAF sensor cleaner.
• Ensure the vehicle is parked on a level surface and the engine is cool. Disconnect the negative battery terminal for safety.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  • Visually inspect all vacuum lines and hoses for cracks or disconnections.
  • If any leaks are found, replace the damaged hoses.
  • Use a smoke machine or propane torch (without igniting) to detect hard-to-find leaks.

3. Check and Clean MAF Sensor

• Sub-steps:
  • Locate the MAF sensor in the intake tract.
  • Disconnect the electrical connector and remove the sensor.
  • Clean the sensor with MAF cleaner and allow it to dry completely.
  • Reinstall the MAF sensor and reconnect the electrical connector.

4. Test and Adjust Fuel Pressure

• Sub-steps:
  • Connect the fuel pressure gauge to the fuel rail.
  • Turn the ignition to the "ON" position (without starting the engine) and check the pressure reading.
  • If the pressure is below the specified range, inspect the fuel pump and fuel filter for issues and replace as necessary.

5. Reset the ECU

• Sub-steps:
  • After repairs are completed, reconnect the negative battery terminal.
  • Start the engine and allow it to reach operating temperature.
  • Use the OBD-II scanner to clear the code and reset the fuel trims.