how to fix P0171 lean code on Tesla Model S Plaid/Refresh (2021-present)

Learn how to diagnose and fix P0171 lean code in Tesla Model S Plaid. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's 12V battery to prevent any electrical short circuits.
• Allow the engine to cool down before starting work.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect all intake hoses and connections for cracks or disconnections.
  2. If any leaks are detected, replace the affected hose or seal.
  3. Use a smoke machine to identify any hidden vacuum leaks.
  4. Reinstall all components securely.

3. Test and Clean MAF Sensor

• Sub-steps:
  1. Disconnect the MAF sensor electrical connector.
  2. Remove the MAF sensor from the air intake housing.
  3. Clean the MAF sensor with MAF cleaner spray, avoiding the use of other solvents.
  4. Reinstall the MAF sensor and reconnect the electrical connector.

4. Check Fuel Pressure

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail service port.
  2. Turn the ignition to the ON position (without starting the engine) and observe the pressure readings.
  3. Compare the readings to the specifications in the service manual. If pressure is low, check the fuel pump and filter.
  4. Replace the fuel filter or fuel pump if necessary.

5. Inspect Fuel Injectors

• Sub-steps:
  1. Remove the fuel rail if necessary to access the injectors.
  2. Check for fuel leaks around the injectors.
  3. Test each injector's resistance with a multimeter; replace any that are out of specs.
  4. Clean the injectors using a professional fuel injector cleaning service if clogged.

6. Verify ECT Sensor Function

• Sub-steps:
  1. Locate the ECT sensor and disconnect its electrical connector.
  2. Use a multimeter to measure resistance against the temperature specifications.
  3. Replace the sensor if readings are outside the acceptable range.