how to fix the P0171 code on my BMW X3 G01 (2018-2024)?

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the vehicle battery to ensure safety.
• Make sure the engine is cool before starting work.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses connected to the intake manifold for cracks and damage.
  2. Use carburetor cleaner or a smoke machine to detect leaks by spraying around suspected areas while the engine is running.
  3. Replace any damaged hoses or seals you find during the inspection.

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Disconnect the MAF sensor's electrical connector.
  2. Remove the sensor from the air intake tubing using a Torx screwdriver.
  3. Clean the sensor with MAF sensor cleaner, avoiding contact with the sensor wires.
  4. If damaged, replace the MAF sensor with a new one and reconnect the electrical connector.

4. Test and Ensure Proper Fuel Pressure

• Sub-steps:
  1. Locate the fuel rail test port and connect the fuel pressure gauge.
  2. Turn the ignition to the "ON" position without starting the engine to prime the system and check the fuel pressure reading.
  3. Refer to the service manual for the correct fuel pressure specifications; if the pressure is low, inspect the fuel pump, filter, and lines.
  4. Replace the fuel filter if it is clogged, and consider replacing the fuel pump if it fails to deliver adequate pressure.

5. Inspect Fuel Injectors

• Sub-steps:
  1. Remove the fuel injectors from the fuel rail carefully.
  2. Use a multimeter to check the resistance of each injector; refer to specifications for expected values.
  3. Clean the injectors with a cleaning solution or replace them if necessary.
  4. Reinstall the injectors ensuring proper seals are used.