how to fix P0171 and P0174 codes in BMW X5 G05 (2019-2024)?

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Vacuum Hoses

• Sub-steps:
  1. Visually inspect all vacuum hoses for cracks, breaks, or loose connections.
  2. If any hoses are damaged, replace them with OEM parts.
  3. Ensure all connections are secure and free from leaks.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner
• Sub-steps:
  1. Locate the MAF sensor in the intake system.
  2. Disconnect the electrical connector from the MAF sensor.
  3. Remove the MAF sensor from the intake tube.
  4. Clean the MAF sensor using MAF sensor cleaner and let it dry completely.
  5. Reinstall the MAF sensor and reconnect the electrical connector.

4. Check and Adjust Fuel Pressure

• Tools Required: Fuel pressure gauge
• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail.
  2. Turn the ignition on without starting the engine and observe the fuel pressure reading.
  3. If the pressure is out of specification, check the fuel pump and filter.
  4. Replace the fuel filter if necessary, and consider replacing the fuel pump if the pressure remains low.

5. Inspect and Test Fuel Injectors

• Tools Required: Multimeter, fuel injector cleaning kit
• Sub-steps:
  1. Disconnect the fuel injector connectors.
  2. Use a multimeter to check for resistance in each injector (specification: typically 12-16 ohms).
  3. If any injectors are out of range, replace them.
  4. If injectors are dirty, use a fuel injector cleaning kit to clean them.

6. Inspect Exhaust System for Leaks

• Sub-steps:
  1. Visually inspect the exhaust manifold and pipes for any visible cracks or holes.
  2. If leaks are found, repair or replace damaged sections of the exhaust system.