how to fix P0171 code in BMW 5 Series G30/G31 (2017-2024)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to avoid electrical shorts during repairs.

2. Inspect and Repair Air Intake System

• Tools Required: Screwdriver set, inspection mirror, flashlight
• Check all vacuum hoses for cracks or disconnections. Replace any damaged hoses.
• Inspect the intake manifold gasket for leaks. Replace if necessary.

3. Clean or Replace MAF Sensor

• Tools Required: MAF cleaner or isopropyl alcohol, soft cloth
• Remove the MAF sensor from the air intake duct.
• Clean the sensor carefully with MAF cleaner and a soft cloth. Allow it to dry completely before reinstalling. If damaged, replace the sensor.

4. Test and Repair Fuel System

• Tools Required: Fuel pressure gauge, socket set
• Connect the fuel pressure gauge to the fuel rail.
• Check the fuel pressure against manufacturer specifications. If low, inspect the fuel pump and filter for blockages or failure.
• Replace the fuel filter if it is clogged or has not been changed per maintenance schedule.

5. Inspect and Clean Throttle Body

• Tools Required: Throttle body cleaner, soft brush
• Remove the intake duct to access the throttle body.
• Clean the throttle body with throttle body cleaner to remove carbon deposits. Ensure the throttle plate moves freely.

6. Reassemble and Reconnect Battery

• Reconnect all components and ensure all connections are secure.
• Reconnect the battery terminal.