how to diagnose P0171 code in Tesla Model S Plaid/Refresh (2021-present)

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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative terminal of the battery to ensure safety while working on electrical components.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, screwdriver, silicone sealant (if needed).
• Inspect all vacuum hoses for cracks or disconnections.
• Use a vacuum gauge to check for proper vacuum levels; repair or replace any faulty hoses.
• If leaks are found, replace hoses as necessary or apply silicone sealant to seal small cracks.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, small Torx screwdriver.
• Locate the MAF sensor in the intake system.
• Disconnect the electrical connector and remove the sensor.
• Clean the sensor with MAF cleaner, avoiding physical contact with the sensor elements.
• Reinstall the MAF sensor and reconnect the electrical connector.

4. Check and Adjust Fuel Pressure

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the Schrader valve on the fuel rail.
• Turn the ignition on (do not start the engine) and check the fuel pressure; it should meet manufacturer specifications.
• If the pressure is low, inspect the fuel pump and fuel filter for issues and replace if necessary.

5. Inspect and Test Fuel Injectors

• Tools Required: Fuel injector tester or multimeter.
• Remove the fuel injectors from the fuel rail.
• Test each injector for resistance with a multimeter; replace any that are out of specification.
• If injectors are clogged, clean them with a professional cleaning kit or replace them.