P2320
Ignition Coil G Secondary Circuit
Ignition system
Generic OBD-II
Medium
What it means
P2320 means the ECM detects a fault in the secondary (high-voltage) circuit of ignition coil 'G' — the side that actually fires the spark plug. A weak or missing spark makes that cylinder misfire, so the engine runs rough and loses a little power. It usually points to a failing coil, a worn spark plug, or a damaged plug boot, and a sustained misfire can damage the catalytic converter.
Medium
Can I keep driving? Usually yes, but the affected cylinder misfires — expect rough running and reduced power, and fix it promptly to protect the catalytic converter.
Common symptoms
What you'll notice
- Check-engine light on (may flash during an active misfire)
- Rough idle or noticeable misfire
- Reduced power and hesitation on acceleration
- Engine may run fine at times, then stumble
Common causes
Most likely first
- Faulty ignition coil 'G' (internal secondary/high-voltage failure)Likely
- Worn spark plug or excessive plug gap on that cylinderCommon
- Damaged plug boot or carbon tracking on the secondary sideCommon
- Faulty ECM (least likely)Less often
How to diagnose & fix
Work through it in order
- Scan and confirm P2320, noting that 'G' identifies the affected coil.
- Inspect the coil's plug boot and the spark plug for wear, damage, or carbon tracks.
- Test the coil's secondary resistance against spec.
- Swap the suspect coil with a known-good one and see if the code follows.
- Replace the coil and/or spark plug as needed, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2320?+
Short trips are usually okay, but a weak secondary circuit means a weak or missing spark on that cylinder, so it misfires. Prolonged misfire can damage the catalytic converter, so repair it soon.
Can I just clear P2320?+
It returns once the secondary fault reappears. Replace the failing coil or spark plug rather than clearing it.
Related codes
Often seen with P2320
Read & clear P2320 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