What it means
A fault is detected on the secondary (high-voltage) side of ignition coil J. The spark delivered to the plug is missing or too weak, causing a misfire on the cylinder served by coil J. Causes: a worn spark plug or wide gap, a cracked coil or boot, carbon tracking, or an open or leaking secondary winding.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The secondary side of ignition coil J produces the high voltage that travels through its boot and spark plug to ignite the cylinder’s mixture. The control module detects an abnormal secondary ignition result, such as spark that is missing or too weak. P2329 points to the coil J ignition path, which can include the plug, boot, or coil’s high-voltage winding.
Common causes
Most likely first.
- Spark plug worn or fouled
- Secondary breakdown inside coil J
Symptoms
- Check-engine light
- Engine misfire or rough running
- Hesitation or reduced power
How to diagnose it
- Save freeze-frame data and review misfire counts to confirm when the cylinder served by coil J misfires.
- Inspect coil J’s boot and the spark plug it serves for cracks, carbon tracks, oil or moisture, fouling, and excessive wear.
- Check the plug gap and condition against the manufacturer’s specification, and inspect the plug well for contamination that could let spark leak away.
- If the design allows, compare coil J with a known-good equivalent coil and see whether the misfire follows the coil.
- Test the coil J secondary winding and related ignition components using the manufacturer’s procedure if the plug and visible parts are sound.
Common fixes
- Clean moisture or oil from the plug well and correct any source of contamination.
- Replace the worn or fouled spark plug served by coil J.
- Replace a cracked or carbon-tracked coil J boot.
- Replace coil J if its secondary output or winding fails the specified test.
Can I keep driving?
Avoid hard acceleration while the engine misfires, and stop if the check-engine light flashes because unburned fuel can damage the catalytic converter. Have the ignition fault addressed promptly if rough running persists.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.