P2323
Ignition Coil H Secondary Circuit
Ignition / misfire
Generic OBD-II
Medium
What it means
P2323 means the ECM has detected a fault in the secondary (high-voltage output) circuit of ignition coil H — the side that fires the spark plug. That cylinder can misfire, causing a rough idle and lost power, and a sustained misfire can damage the catalytic converter, so it should be repaired promptly.
Medium
Can I keep driving? Drivable but expect a misfire on that cylinder — if the check-engine light flashes, drive as little as possible to protect the catalytic converter.
Common symptoms
What you'll notice
- Check-engine light on (may flash during an active misfire)
- Rough idle, stumble, or hesitation
- Loss of power on acceleration
- Slightly increased fuel consumption
Common causes
Most likely first
- Faulty ignition coil H (secondary/high-voltage side)Likely
- Worn or fouled spark plug on that cylinderCommon
- Cracked coil boot or arcing to groundCommon
- Corroded or loose coil connectorLess often
- Excessive spark plug gap or wrong plugLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and note which cylinder coil H feeds.
- Remove and inspect that cylinder's spark plug for wear, fouling, or wrong gap.
- Inspect the coil boot for cracks, carbon tracking, or arcing.
- Swap coil H with a known-good coil and see if the fault follows the coil.
- Replace the coil and/or plug as needed, then clear and confirm the misfire is gone.
FAQ
Quick answers
Is it safe to drive with P2323?+
Only briefly. A steady misfire sends raw fuel into the exhaust and can overheat the converter — a flashing light means stop driving soon.
Can I just clear P2323?+
It returns quickly because the ECM keeps monitoring the coil's secondary output until the coil or plug is repaired.
Related codes
Often seen with P2323
Read & clear P2323 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX