how to fix P0174 code in my BMW 5 Series G30/G31 (2017-2024)?

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool down.

2. Inspect and Repair Vacuum Leaks

• Visually inspect all vacuum hoses and connections for wear or damage.
• Use a smoke machine to detect any leaks in the intake system.
• Replace any damaged hoses or seals as needed.

3. Clean or Replace MAF Sensor

• Locate the MAF sensor in the intake duct.
• Disconnect the electrical connector and remove the sensor using a Torx screwdriver.
• Clean the MAF sensor using MAF cleaner spray and allow it to dry completely. If damaged, replace it with a new one.
• Reinstall the MAF sensor and reconnect the electrical connector.

4. Check and Replace Fuel Filter

• Locate the fuel filter (usually near the fuel tank).
• Relieve fuel system pressure by removing the fuel pump fuse and starting the engine until it stalls.
• Disconnect fuel lines from the filter using a fuel line disconnect tool.
• Replace the old filter with a new one, ensuring proper orientation.
• Reconnect fuel lines securely.

5. Inspect and Clean Fuel Injectors

• Remove the fuel rail according to the service manual.
• Take out the fuel injectors from the rail.
• Clean the injectors using an ultrasonic cleaner or replace them if faulty.
• Reinstall the injectors and fuel rail.

6. Reset the ECM

• Reconnect the negative battery terminal.
• Use an OBD-II scanner to clear the P0174 code from the ECM.
• Start the engine and check for any reoccurring codes.