how to resolve 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

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, vacuum gauge.
• Disconnect the battery to prevent any electrical shorts.
• Allow the engine to cool before beginning work.

2. Inspect Spark Plugs

• Sub-steps:
  1. Remove the engine cover using a socket set.
  2. Disconnect the ignition coil connectors from cylinder 1.
  3. Remove the ignition coil from cylinder 1 using the socket set.
  4. Unscrew and remove the spark plug from cylinder 1 with a spark plug socket.
  5. Inspect the spark plug for signs of wear, carbon buildup, or damage.
  6. Replace the spark plug if necessary, ensuring proper gap specifications are met (typically 0.020-0.028 inches for Tesla).
  7. Reinstall the ignition coil and reconnect the connector.

3. Inspect and Test Ignition Coil

• Sub-steps:
  1. Remove the ignition coil from cylinder 1 (if not already done).
  2. Use a multimeter to measure the resistance of the ignition coil.
     • Primary resistance: 0.5 - 1.5 ohms.
     • Secondary resistance: 6,000 - 15,000 ohms.
  3. Replace the ignition coil if resistance values are out of specifications.
  4. Reinstall the ignition coil and reconnect the connector.

4. Check for Vacuum Leaks

• Sub-steps:
  1. Use a vacuum gauge to measure the vacuum at the intake manifold.
  2. If vacuum is low, inspect hoses and the intake manifold gasket for leaks.
  3. Perform a smoke test if necessary to locate hard-to-find leaks.
  4. Replace any damaged hoses or gaskets.

5. Perform a Compression Test

• Sub-steps:
  1. Remove spark plugs from all cylinders for accurate readings.
  2. Insert the compression tester into the spark plug hole of cylinder 1.
  3. Crank the engine for several seconds to get a reading.
  4. Compare the compression result to factory specifications (typically around 180-210 psi).
  5. If compression is low, further investigation is needed for possible internal engine issues.