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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.
• Allow the engine to cool before starting.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, screwdriver set
• Use the vacuum gauge to check for leaks in the intake system.
• Visually inspect all hoses and connections for cracks or disconnections.
• Replace any damaged hoses or gaskets found during inspection.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, screwdrivers
• Remove the MAF sensor from the intake duct.
• Spray the MAF sensor with MAF cleaner, avoiding contact with any internal components.
• Allow it to dry completely before reinstalling. If damaged, replace with a new sensor.

4. Check Fuel Pressure

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail.
• Start the engine and observe the pressure reading; it should match the manufacturer’s specifications (usually 50-60 psi for BMW).
• If the pressure is low, check the fuel pump and filter for issues, replacing them if necessary.

5. Inspect and Test Fuel Injectors

• Tools Required: Multimeter, fuel injector cleaner
• Remove the fuel injectors from the engine.
• Test each injector with a multimeter to ensure proper resistance.
• Clean the injectors using a professional fuel injector cleaning kit. Replace any injectors that fail the resistance test.

6. Reconnect Battery and Clear Codes

• Reconnect the battery once repairs are completed.
• Use the OBD-II scanner to clear the P0174 code and any other stored codes.