how to diagnose a P0301 code on a Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to ensure safety while working on electrical components.

2. Replace Spark Plug

• Remove the engine cover (if applicable) using a socket set.
• Locate the spark plug for cylinder 1.
• Using a spark plug socket, remove the old spark plug.
• Inspect the old spark plug for wear; if it is fouled or damaged, replace it with a new one.
• Torque the new spark plug to the manufacturer's specifications (typically 13-16 lb-ft).
• Reinstall the engine cover.

3. Replace Ignition Coil

• Disconnect the electrical connector from the ignition coil.
• Remove the bolt securing the ignition coil and lift it out of the spark plug well.
• Install the new ignition coil and secure it with the bolt.
• Reconnect the electrical connector.

4. Check Fuel Injector

• Remove the fuel injector connector for cylinder 1.
• Use a multimeter to check the resistance of the fuel injector (should typically be around 12-16 ohms).
• If the injector is faulty, remove the intake manifold (if necessary) and replace the injector.
• Reinstall the injector and reconnect the connector.

5. Clear Codes and Test Drive

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0301 code.
• Start the engine and perform a test drive to ensure the code does not reappear.