how to fix P0171 code on BMW 5 Series G30/G31 (2017-2024)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery cable to prevent electrical shorts.

2. Inspect and Repair Air Intake System

• Tools Required: Socket set, screwdrivers, vacuum gauge
• Sub-steps:
  1. Visually inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
  2. Tighten or replace any loose or damaged hoses.
  3. Remove the air intake duct and inspect it for damage or blockages.
  4. Reinstall the air intake duct securely.

3. Clean or Replace MAF Sensor

• Tools Required: MAF cleaner, torx screwdriver
• Sub-steps:
  1. Disconnect the MAF sensor electrical connector.
  2. Remove the MAF sensor from the air intake system.
  3. Spray MAF cleaner on the sensor element and allow it to dry completely.
  4. Reinstall the MAF sensor and reconnect the electrical connector.

4. Check Fuel System

• Tools Required: Fuel pressure gauge
• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail test port.
  2. Turn the ignition on (do not start the engine) and check the fuel pressure.
  3. Ensure the fuel pressure is within specifications (refer to service manual for exact values).
  4. If pressure is low, inspect the fuel pump, fuel filter, and fuel injectors for issues.

5. Inspect Oxygen Sensors and Exhaust System

• Tools Required: O2 sensor socket, multimeter
• Sub-steps:
  1. Visually inspect the exhaust system for any leaks.
  2. Test the upstream oxygen sensor using a multimeter to ensure it is functioning correctly.
  3. Replace the oxygen sensor if readings are outside of normal parameters.
  4. Repair any exhaust leaks found during inspection.