how to fix P0171 code in BMW 5 Series F10/F11 (2010-2017)

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative terminal of the battery.
• Ensure the engine is cool before starting work.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum lines and hoses for cracks or disconnections.
  2. Use a smoke machine or carb cleaner to identify leaks; apply carb cleaner near suspected areas while the engine is running. If RPM changes, there is a leak.
  3. Replace any damaged hoses or gaskets as necessary.

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake duct.
  2. Disconnect the electrical connector and remove the sensor.
  3. Use MAF sensor cleaner to spray the sensor element and allow it to dry completely.
  4. If the sensor is damaged, replace it with a new one.
  5. Reinstall the MAF sensor and reconnect the electrical connector.

4. Check and Repair Fuel System

• Sub-steps:
  1. Use a fuel pressure gauge to measure the fuel system pressure; it should meet manufacturer specifications (usually around 50-60 psi).
  2. If pressure is low, inspect the fuel pump, fuel filter, and fuel lines for blockages or damage.
  3. Replace the fuel filter if clogged and consider replacing the fuel pump if it doesn’t meet pressure requirements.

5. Inspect Fuel Injectors

• Sub-steps:
  1. Remove the fuel rail to access the injectors.
  2. Inspect injectors for clogs or leaks. Clean with an ultrasonic cleaner if necessary.
  3. Test injectors with a multimeter to ensure they are functioning correctly.
  4. Replace any faulty injectors.