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

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Repair Intake System

1. Visual Inspection

   • Check all air intake hoses and connections for visible damage or disconnections.
   • Tighten any loose clamps or fittings.

2. Replace Damaged Parts

   • If any hoses are cracked or damaged, replace them with OEM parts.
   • Ensure all connections are secure.

3. Test and Clean MAF Sensor

1. Remove MAF Sensor

   • Disconnect the electrical connector.
   • Use a Torx screwdriver to remove the MAF sensor from the air intake duct.

2. Clean MAF Sensor

   • Spray MAF sensor cleaner onto the sensor element.
   • Allow it to dry completely before reinstallation.

3. Reinstall MAF Sensor

   • Secure the MAF sensor back into its housing and reconnect the electrical connector.

4. Check and Adjust Fuel Pressure

1. Connect Fuel Pressure Gauge

   • Locate the fuel rail and attach the fuel pressure gauge to the Schrader valve.

2. Measure Fuel Pressure

   • Turn the ignition to the "ON" position (do not start the engine) and check the pressure reading.
   • Compare the reading with manufacturer specifications (usually around 50-60 psi).

3. Replace Fuel Pump or Filter if Necessary

   • If pressure is low, inspect and replace the fuel filter or fuel pump as needed.

5. Inspect and Replace Oxygen Sensors

1. Check Oxygen Sensors

   • Using a multimeter or scan tool, check the response of the upstream O2 sensor.

2. Replace Faulty Sensors

   • If the sensor is not functioning properly, remove it using an O2 sensor socket and replace it with a new one.