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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, screwdriver set.
• Visually inspect all vacuum hoses and connections for cracks or disconnections.
• Use a vacuum gauge to check for proper vacuum levels.
• Repair or replace any damaged hoses or connections.

3. Clean or Replace MAF Sensor

• Tools Required: MAF cleaner or isopropyl alcohol, soft cloth.
• Locate the MAF sensor in the air intake duct.
• Disconnect the electrical connector and remove the sensor from the housing.
• Clean the sensor using MAF cleaner; do not touch the sensor elements.
• Reinstall the cleaned sensor or replace it if damaged.

4. Check Fuel System

• Tools Required: Fuel pressure gauge, multimeter.
• Check fuel pressure at the fuel rail with a gauge; compare to manufacturer specifications.
• If pressure is low, inspect the fuel pump and filter for clogs or failures.
• Test fuel injectors for proper operation using a multimeter; replace any faulty injectors.

5. Inspect Exhaust System

• Tools Required: Visual inspection tools, flashlight.
• Examine the exhaust system for any leaks, particularly before the oxygen sensor.
• Repair any identified leaks using appropriate exhaust sealant or by replacing damaged components.

6. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0174 code.
• Start the engine and monitor for any reoccurrence of the code.