P2329
Ignition Coil J Secondary Circuit
Ignition / misfire
Generic OBD-II
Medium
What it means
P2329 flags a fault in the secondary — high-voltage — side of ignition coil 'J', the part that fires the spark plug. It usually points to a failed coil, a worn plug, or a damaged plug boot on that cylinder. The result is a misfire with rough running and lost power, which can harm the catalytic converter if left unrepaired.
Medium
Can I keep driving? You can usually drive, but that cylinder may misfire; a sustained misfire can overheat the converter, so repair it soon.
Common symptoms
What you'll notice
- Misfire, rough idle, or shaking
- Hesitation and reduced power on acceleration
- Check-engine light on (may flash during an active misfire)
- Slightly increased fuel consumption
Common causes
Most likely first
- Fault in the secondary (high-voltage) side of ignition coil JLikely
- Failed coil J or a worn spark plug on that cylinderCommon
- Damaged plug boot, wire, or high-voltage connectionCommon
- Corroded coil connector or damaged wiringLess often
- Faulty ECM (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and identify which cylinder coil 'J' feeds.
- Inspect the spark plug, boot, and coil for arcing, cracks, or carbon tracking.
- Swap coil J with a known-good coil to see if the fault follows the coil.
- Replace a worn plug and test the coil; replace the coil if it fails the secondary check.
- If the coil and plug are good, inspect wiring and the ECM. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2329?+
For a short distance, but a misfiring cylinder can damage the catalytic converter. Repair it soon, and stop driving if the check-engine light is flashing.
Can I just clear P2329?+
It returns until the coil's secondary fault, plug, or wiring is repaired. Clear it afterward to confirm the fix.
Related codes
Often seen with P2329
Read & clear P2329 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