how to fix my BMW 5 Series F10/F11 (2010-2017) with a check engine light on for P0174

Solution

1. Preparation

• Tools Required: OBD-II scanner, vacuum gauge, multimeter, torque wrench, socket set, cleaning supplies (MAF cleaner), fuel pressure gauge.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to avoid any electrical shorts.

2. Inspect and Repair Intake System

• Sub-steps:
  1. Visually inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
  2. Replace any damaged hoses and ensure all connections are secure.
  3. Check the intake manifold gasket for leaks and replace if necessary.

3. Clean MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the intake system (usually located between the air filter and throttle body).
  2. Disconnect the electrical connector from the MAF sensor.
  3. Remove the MAF sensor using the appropriate socket.
  4. Clean the sensor with MAF cleaner and allow it to dry completely before reinstalling.
  5. Reinstall the sensor and reconnect the electrical connector.

4. Check Fuel Pressure

• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position without starting the engine, and check the fuel pressure reading.
  3. If the pressure is below specifications (consult the service manual for specific values), inspect the fuel pump and filter for issues.

5. Inspect and Test Oxygen Sensors

• Sub-steps:
  1. Using a multimeter, check the output voltage of the oxygen sensors.
  2. If the readings are outside of the standard range, consider replacing the affected sensor(s).
  3. Reconnect all components securely after inspection.