how to diagnose P0301 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, multimeter, compression tester, socket set, torque wrench, spark plug socket, fuel injector cleaning kit.
• Disconnect the vehicle's battery to ensure safety when working on electrical systems.

2. Replace Spark Plug

• Remove the engine cover (if applicable).
• Use the spark plug socket to remove the spark plug from cylinder 1.
• Inspect the spark plug: if it is worn or damaged, replace it with a new one (follow manufacturer's specifications for gap size).
• Torque the new spark plug to the manufacturer's specifications (typically around 18-22 lb-ft).

3. Test and Replace Ignition Coil

• Disconnect the ignition coil connector.
• Use the multimeter to check the resistance of the ignition coil; reference the manufacturer's specifications.
• If the ignition coil is faulty, remove it from cylinder 1 and replace it with a new one, ensuring it is seated properly.

4. Clean or Replace Fuel Injector

• If the fuel injector is suspected to be clogged, remove it using the appropriate socket.
• Clean the injector using a fuel injector cleaning kit, or replace it if it is not functioning properly.
• Reinstall the fuel injector and ensure it is properly connected.

5. Perform Compression Test

• Remove the spark plug from cylinder 1 and install the compression tester.
• Crank the engine several times to obtain a reading; compare the results to the manufacturer's specifications.
• If compression is low, further investigation may be required to determine the underlying cause.

6. Reassemble and Test

• Reconnect all removed components, ensuring all connections are secure.
• Reconnect the battery and start the vehicle to check for the check engine light and ensure smooth operation.