how to fix P0171 code in BMW X5 F15 (2014-2019)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative terminal of the battery.
• Allow the engine to cool down before starting work.

2. Inspect and Repair Vacuum Leaks

1. Visually inspect all vacuum lines for cracks or disconnections.
2. Use a smoke machine or carburetor cleaner to detect leaks.
3. Replace any damaged hoses or gaskets identified during inspection.

3. Clean or Replace MAF Sensor

1. Locate the MAF sensor connected to the air intake duct.
2. Disconnect the electrical connector and remove the sensor from the duct.
3. Clean the MAF sensor with MAF cleaner spray, allowing it to dry completely.
4. If the sensor is damaged, replace it with a new one.

4. Check and Replace Fuel Filter (if necessary)

1. Locate the fuel filter under the vehicle.
2. Relieve fuel pressure by removing the fuel pump fuse and starting the engine until it stalls.
3. Disconnect the fuel lines from the filter using a line wrench.
4. Replace the old filter with a new one, ensuring proper orientation.
5. Reconnect the fuel lines and replace the fuel pump fuse.

5. Inspect and Clean Fuel Injectors

1. Remove the fuel rail by disconnecting the necessary bolts and fuel lines.
2. Carefully remove the fuel injectors from the rail.
3. Use an injector cleaner to clean each injector or replace them if necessary.
4. Reassemble the fuel rail and reconnect it to the engine.