OBD-II Generic Error Code P2305: How to Fix Ignition Coil B Secondary Circuit

Q: Can I drive with the P2305 code?

You can drive short distances, but it's not recommended. The misfire can cause damage to the catalytic converter and reduce fuel economy. Address the issue promptly.

Q: What does 'Ignition Coil B Secondary Circuit' mean?

The secondary circuit of the ignition coil is the output side that generates high voltage to fire the spark plug. A fault in this circuit means the coil is not producing enough voltage or has an open/short in the secondary winding.

Q: Can a bad spark plug cause P2305?

Yes, a worn or fouled spark plug can put excessive load on the ignition coil, causing secondary circuit faults. Always inspect the spark plug for the affected cylinder and replace if needed.

Q: How much does it cost to fix error P2305?

DIY cost for a single ignition coil is typically $30-$80, plus a spark plug if needed ($5-$20). Professional repair including diagnostic fee can range from $150 to $300.

Q: Will P2305 clear itself after replacing the coil?

No, the code remains stored in the ECU until cleared with an OBD-II scanner. After repair, use a scanner to clear the code and verify the fix.

Abstract

Error code P2305 indicates a problem with the secondary circuit of ignition coil B (the coil that fires cylinder number 2 in most engines). This can cause misfires, rough running, and reduced fuel economy. The fix typically involves testing and replacing the ignition coil, though wiring or connector issues can also be the culprit.