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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery before starting any electrical work.
• Allow the engine to cool before opening any components.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, and replacement gaskets if needed.
• Check all vacuum lines connected to the intake manifold for cracks or disconnections.
  • Use a vacuum gauge to test for leaks.
  • Replace any damaged hoses or loose connections.
• Inspect the intake manifold gasket for integrity and replace if necessary.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner.
• Disconnect the MAF sensor connector.
• Remove the MAF sensor from the intake duct.
• Clean the sensor using a dedicated MAF cleaner. Allow it to dry completely before reinstalling.
• If cleaning does not resolve the issue, replace the MAF sensor with a new one.

4. Check Fuel System

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the fuel rail.
• Start the engine and monitor the fuel pressure. It should match the specifications listed in the service manual.
• If the fuel pressure is low, inspect the fuel pump and filter for issues and replace them as necessary.

5. Inspect Oxygen Sensors

• Tools Required: O2 sensor socket.
• Inspect the upstream and downstream oxygen sensors for damage or corrosion.
• Test the sensors' functionality using a multimeter. Replace any malfunctioning sensors with new ones.