how to diagnose P0301 misfire code on Tesla Model 3 Original (2017-2023)

Solution

1. Preparation

• Tools Required: OBD-II scanner, spark plug socket, compression gauge, multimeter, torque wrench, basic hand tools.
• Ensure the vehicle is on a level surface and the engine is cool.

2. Inspect and Replace Ignition Coil

• Sub-steps:
  1. Disconnect the negative battery terminal to prevent electrical shorts.
  2. Locate the ignition coil for cylinder 1.
  3. Unplug the electrical connector from the ignition coil.
  4. Remove the mounting bolts using a socket set and carefully lift the coil out.
  5. Install the new ignition coil and tighten to manufacturer specifications (typically around 10-15 Nm).
  6. Reconnect the electrical connector.

3. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the ignition coil as described in the previous step.
  2. Use a spark plug socket to remove the spark plug from cylinder 1.
  3. Inspect the spark plug for signs of wear or damage; replace it if necessary.
  4. Check the gap with a feeler gauge and adjust it according to manufacturer specifications (usually around 0.8 mm).
  5. Install the new or cleaned spark plug and torque to manufacturer specifications (typically around 20-25 Nm).
  6. Reinstall the ignition coil.

4. Check Fuel Injector

• Sub-steps:
  1. Remove the intake manifold if required to access the fuel injector for cylinder 1.
  2. Disconnect the electrical connector from the fuel injector.
  3. Use a multimeter to check the resistance of the injector (should typically be around 12-16 ohms).
  4. If the injector is faulty, replace it with a new one.
  5. Reconnect the electrical connector and reassemble any components removed.

5. Perform Compression Test

• Sub-steps:
  1. Remove the spark plug from cylinder 1.
  2. Insert the compression gauge into the spark plug hole.
  3. Crank the engine a few times and record the compression reading (should be within manufacturer specifications, usually 150-200 psi).
  4. If compression is low, further inspection of engine internals may be necessary.