how to troubleshoot P0301 code in Toyota Corolla E210 (2019-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is off and cool.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect and Replace Ignition Coil

• Tools Required: Socket set, torque wrench
• Sub-steps:
  1. Remove the engine cover (if applicable) to access the ignition coil.
  2. Disconnect the electrical connector from the ignition coil for cylinder 1.
  3. Remove the mounting bolts securing the ignition coil and pull it out gently.
  4. Install the new ignition coil and secure it with bolts to the manufacturer's torque specifications (typically 7-9 ft-lbs).
  5. Reconnect the electrical connector.

3. Inspect and Replace Spark Plug

• Tools Required: Spark plug socket, torque wrench
• Sub-steps:
  1. Remove the ignition coil from cylinder 1 if it hasn't been removed yet.
  2. Use a spark plug socket to unscrew and remove the spark plug from cylinder 1.
  3. Inspect the spark plug for wear and ensure the gap is within the manufacturer's specifications (typically 0.043 inches).
  4. Install a new spark plug and torque it to the manufacturer's specifications (typically 13 ft-lbs).
  5. Reinstall the ignition coil.

4. Test and Replace Fuel Injector (if necessary)

• Tools Required: Fuel injector tester or multimeter
• Sub-steps:
  1. Disconnect the fuel injector connector from cylinder 1.
  2. Use a multimeter to test the injector's resistance (typically 12-16 ohms).
  3. If the injector is faulty, remove it using the appropriate tool and install a new one.
  4. Reconnect the fuel injector connector.

5. Check Compression (if misfire persists)

• Tools Required: Compression tester
• Sub-steps:
  1. Remove the spark plug from cylinder 1.
  2. Insert the compression tester into the spark plug hole.
  3. Crank the engine a few times to take a reading.
  4. Compare the reading to the manufacturer's specifications (typically 180-220 psi).
  5. If the compression is low, further diagnosis may be required for internal engine issues.