how to fix P0300 misfire code on Tesla Model S Plaid/Refresh (2021-present)

Learn how to diagnose and fix P0300 engine 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 high voltage battery following the manufacturer's guidelines.

2. Inspect Battery Connections

• Sub-steps:
  1. Remove the access panels to the battery compartment.
  2. Inspect all battery connections for corrosion or looseness.
  3. Tighten any loose connections and clean corroded terminals with a wire brush.

3. Check Ignition Components (if applicable)

• Sub-steps:
  1. Remove the covers to access the ignition coils (if equipped).
  2. Inspect the ignition coils for cracks or damage; replace if necessary.
  3. Remove and inspect the spark plugs; replace any that show wear or fouling.
  4. Reinstall the ignition coils and covers.

4. Inspect Wiring and Connectors

• Sub-steps:
  1. Visually inspect wiring harnesses for any signs of wear or damage.
  2. Check all connectors for tightness and cleanliness; clean or replace as needed.
  3. Ensure all ground connections are secure and free of corrosion.

5. Reset the OBD-II System

• Sub-steps:
  1. Reconnect the high voltage battery.
  2. Use an OBD-II scanner to clear the P0300 code from the system.
  3. Perform a test drive to monitor the vehicle's performance and verify the repair.