how to diagnose P0171 code on my Tesla Model 3 Highland (2024-present)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses and connections for cracks or disconnections.
  2. If leaks are found, replace damaged hoses or reattach loose connections.
  3. Use a smoke machine to identify any hard-to-find leaks.

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake system.
  2. Disconnect the electrical connector and remove the sensor using an appropriate socket.
  3. Clean the sensor with MAF cleaner spray and a soft cloth; do not touch the sensor elements.
  4. Reinstall the MAF sensor and reconnect the electrical connector.

4. Check and Adjust 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 to check pressure readings.
  3. If pressure is below specifications, check the fuel pump and filter for issues; replace as necessary.

5. Replace Oxygen Sensors (if faulty)

• Sub-steps:
  1. Disconnect the electrical connectors from the upstream and downstream oxygen sensors.
  2. Using an oxygen sensor socket, remove the sensors from the exhaust system.
  3. Install the new sensors by reversing the removal process and ensuring proper torque specifications.
  4. Reconnect the electrical connectors.