how to fix P0174 code on BMW 5 Series F10/F11 (2010-2017)

Solution

1. Preparation

• Gather required tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before starting work.

2. Inspect and Replace Vacuum Hoses

• Sub-steps:
  1. Visually inspect all vacuum hoses for cracks or leaks.
  2. Replace any damaged hoses with OEM or quality aftermarket hoses.
• Tools Required:
  • Pliers
  • Hose cutter

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the intake duct.
  2. Disconnect the electrical connector and remove the MAF sensor from the housing.
  3. Clean the sensor using MAF cleaner or replace it if damaged.
  4. Reinstall the sensor and reconnect the electrical connector.
• Tools Required:
  • Torx screwdriver
  • MAF cleaner (if cleaning)

4. Check Fuel Delivery System

• Sub-steps:
  1. Use a fuel pressure gauge to measure fuel pressure at the fuel rail.
  2. Compare the reading with the manufacturer specifications (typically 50-60 psi for BMW).
  3. If the pressure is low, inspect the fuel pump and fuel filter for blockages or failures.
• Tools Required:
  • Fuel pressure gauge

5. Inspect Intake Manifold and Gaskets

• Sub-steps:
  1. Remove the intake manifold cover to access the gaskets.
  2. Inspect the gaskets for wear or damage and replace if necessary.
  3. Tighten any loose bolts to the specified torque (typically 10-15 Nm).
• Tools Required:
  • Torque wrench
  • Socket set

6. Replace Faulty Oxygen Sensors (if needed)

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Disconnect the electrical connector and remove the sensor using an O2 sensor socket.
  3. Install the new sensor and reconnect the electrical connector.
• Tools Required:
  • O2 sensor socket
  • Wrench