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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool if recently operated.

2. Inspect and Repair Intake System

1. Visually inspect all vacuum lines for cracks or disconnections.
2. Tighten any loose clamps and replace damaged hoses.
3. Use smoke testing to detect hard-to-find vacuum leaks.

3. Clean or Replace MAF Sensor

1. Remove the MAF sensor from the intake ducting.
2. Use MAF cleaner to spray and clean the sensor element gently.
3. Allow the sensor to dry completely before reinstalling.
4. If the sensor is damaged, replace it with a new one.

4. Check and Repair Fuel System

1. Connect a fuel pressure gauge to the fuel rail.
2. Start the engine and check the fuel pressure; it should match manufacturer specifications (typically around 50-60 psi).
3. If pressure is low, inspect the fuel pump, filter, and relay for faults and replace as needed.

5. Inspect and Replace Oxygen Sensors

1. Remove the oxygen sensors from the exhaust system using an O2 sensor socket.
2. Inspect the sensor for signs of damage or contamination.
3. If faulty, replace with new sensors, ensuring proper torque specifications are followed during installation.