how to diagnose P0300 code in Toyota Corolla E210 (2019-2024)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.
• Raise the vehicle if required for better access.

2. Inspect and Replace Spark Plugs

• Remove the ignition coils by unscrewing the bolts or clips, depending on the design.
• Carefully pull out the spark plugs using a spark plug socket.
• Inspect the spark plugs for wear or fouling; replace if necessary with OEM-spec plugs.
• Install new spark plugs and torque to the specified value (typically around 13-15 lb-ft).

3. Check and Replace Ignition Coils

• Test ignition coils for proper resistance using a multimeter (consult manufacturer's specifications).
• Replace any faulty ignition coils with OEM parts.
• Reinstall the ignition coils and ensure they are properly secured.

4. Fuel Injector Testing

• Remove fuel injector connectors and perform a resistance test to ensure they are within specifications.
• Clean or replace any fuel injectors that are malfunctioning.
• Reconnect the fuel injectors and ensure a secure connection.

5. Fuel Pressure Test

• Connect the fuel pressure gauge to the fuel rail service port.
• Turn the ignition to the "ON" position (do not start the engine) to check for initial fuel pressure.
• Start the engine and observe the fuel pressure; it should match manufacturer specifications (typically 43-50 psi).
• If pressure is low, check the fuel pump and filter for issues.