how to diagnose P0301 misfire code in Tesla Model S Plaid/Refresh (2021-present)

Learn how to diagnose and fix P0301 cylinder 1 misfire in Tesla Model S Plaid. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the parking brake is engaged.
• Disconnect the battery to prevent electrical shock or short circuits.

2. Inspect Ignition Components

• Remove the engine cover if applicable.

• Spark Plug Replacement:

  • Use a spark plug socket to remove the spark plug from cylinder 1.
  • Inspect the spark plug for carbon buildup or wear.
  • Replace with new spark plug (specify OEM part).
  • Torque to manufacturer specifications (typically around 15 ft-lbs).

• Ignition Coil Replacement:

  • Remove the ignition coil from cylinder 1.
  • Inspect for cracks or corrosion.
  • Replace with new ignition coil (specify OEM part).

3. Check Fuel Delivery

• Fuel Injector Inspection:

  • Remove the fuel rail assembly if necessary.
  • Inspect fuel injector for clogs; clean or replace as needed.
  • Ensure proper seating of the injector upon reinstallation.

• Fuel Pump Test:

  • Use a fuel pressure gauge to check for proper fuel pressure at the rail.
  • If pressure is low, check fuel pump operation or replace if faulty.

4. Compression Test

• Remove the spark plug from cylinder 1.
• Insert a compression gauge into the spark plug hole.
• Crank the engine and read the compression; values should be within manufacturer specifications (typically around 180-210 psi).
• If compression is low, further investigation is needed for piston rings or valve seals.

5. Reassemble and Reconnect

• Reinstall all components in reverse order.
• Reconnect the battery.
• Ensure all connections are tight and secure.