how to troubleshoot P0301 code in my Honda Accord Eleventh Generation (2023-present)

Solution

1. Preparation

• Tools Required: OBD-II scanner, spark plug socket, multimeter, compression tester, noid light, basic hand tools.
• Safety Warning: Disconnect the battery before starting work on electrical systems.

2. Replace Spark Plug

• Remove the engine cover if necessary.
• Disconnect the ignition coil connector and remove the ignition coil from cylinder 1.
• Use a spark plug socket to remove the spark plug and inspect for wear.
• Install a new spark plug with the correct gap (refer to the owner's manual for specifications).
• Reinstall the ignition coil and connector.

3. Test and Replace Ignition Coil (if necessary)

• Use a multimeter to measure the primary and secondary resistance of the ignition coil.
  • Primary resistance: typically between 0.4 to 2 ohms.
  • Secondary resistance: usually between 6,000 to 15,000 ohms.
• If out of specification, replace the ignition coil with a new one.
• Reconnect the ignition coil and ensure it is secured.

4. Inspect Fuel Injector

• Disconnect the fuel injector connector for cylinder 1.
• Use a noid light to check for injector pulse while cranking the engine. If no pulse is detected, a wiring issue or ECM fault may be present.
• If operation is faulty, replace the fuel injector.

5. Compression Test

• Remove the spark plug from cylinder 1.
• Insert the compression tester into the spark plug hole.
• Crank the engine for a few seconds and read the compression level.
• Compare the reading with the manufacturer’s specifications (usually around 180-200 psi).
• If compression is low, further diagnosis is required for internal engine issues.