how to fix P0171 code in BMW X5 G05 (2019-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to prevent electrical shorts.
• Allow the engine to cool before working on components.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  • Visually inspect all vacuum hoses connected to the intake manifold.
  • Use a smoke machine or carburetor cleaner to identify any leaks around the intake manifold gasket and vacuum hoses.
  • Replace any damaged hoses or gaskets.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Disconnect the MAF sensor connector.
  • Remove the MAF sensor from its housing (typically held by Torx screws).
  • Clean the MAF sensor using MAF cleaner spray; do not use any other cleaner.
  • Allow it to dry completely before reinstallation.
  • Reinstall the MAF sensor and reconnect the connector.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  • Locate the fuel pressure test port on the fuel rail.
  • Attach the fuel pressure gauge and turn the ignition to the "ON" position without starting the engine.
  • Check the fuel pressure reading against the specifications in the service manual.
  • If pressure is low, check the fuel filter and pump for clogs or failures. Replace as necessary.

5. Inspect and Clean Fuel Injectors

• Sub-steps:
  • Remove the fuel injector rail carefully to avoid damage.
  • Inspect each injector for clogs or leaks.
  • Clean injectors using an ultrasonic cleaner or replace them if they are damaged.

6. Reconnect Battery and Clear Codes

• Reconnect the battery terminals securely.
• Use the OBD-II scanner to clear the P0171 code and any other stored codes.