how to fix P0174 code in BMW 5 Series F10/F11 (2010-2017)

Solution

1. Preparation

• Tools Required: OBD-II scanner, vacuum gauge, fuel pressure gauge, MAF sensor cleaner, basic hand tools.
• Verify that the vehicle is parked on a level surface and the engine is off. Disconnect the battery to ensure safety while working on electrical components.

2. Inspect Intake System

• Sub-steps:
  1. Visually inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
  2. Use a vacuum gauge to check for leaks. If a leak is detected, replace the faulty hose or gasket.
  3. Inspect the intake manifold gasket and replace it if damaged.

3. Clean MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the intake air duct.
  2. Disconnect the electrical connector and the sensor from the duct.
  3. Use MAF sensor cleaner to spray the sensor elements, allowing it to dry completely before reinstallation.
  4. Reconnect the MAF sensor and electrical connector.

4. Check Fuel Pressure

• Sub-steps:
  1. Locate the fuel pressure test port on the fuel rail.
  2. Connect the fuel pressure gauge to the test port.
  3. Turn the ignition to the "ON" position (do not start the engine) and check the pressure. It should match manufacturer specifications (typically around 50-60 psi).
  4. If the pressure is low, check the fuel pump and filter for issues.

5. Inspect Fuel Injectors

• Sub-steps:
  1. Remove the fuel rail assembly carefully, taking note of the injector connections.
  2. Inspect each injector for clogs or leaks. If necessary, clean or replace the injectors.
  3. Reinstall the fuel rail, ensuring proper seating of the injectors.

6. Replace Faulty O2 Sensors (if necessary)

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors on Bank 2.
  2. Disconnect the electrical connectors and use an O2 sensor socket to remove the sensors.
  3. Install new sensors, ensuring they are torqued to the manufacturer's specifications.
  4. Reconnect the electrical connectors.