P2302
Ignition Coil 'A' Secondary Circuit
Ignition system
Generic OBD-II
Medium
What it means
P2302 means the ECM detected a fault in the secondary (high-voltage) side of ignition coil 'A' — the part that fires the spark plug. This usually causes a misfire on that cylinder, so the engine runs rough and loses a little power. The typical cause is a failing coil, a cracked boot or plug wire, or a worn spark plug. Repair it promptly, since a sustained misfire can damage the catalytic converter.
Medium
Can I keep driving? Usually yes, but expect a misfire and rough running on that cylinder; sustained misfiring can damage the catalytic converter, so repair it soon.
Common symptoms
What you'll notice
- Check-engine light on, sometimes flashing during a misfire
- Rough idle and an intermittent stumble or miss
- Hesitation and reduced power on acceleration
- Slightly higher fuel consumption
Common causes
Most likely first
- Faulty ignition coil 'A' (secondary/high-voltage side)Likely
- Cracked or carbon-tracked coil boot or spark-plug wireCommon
- Worn or fouled spark plug on that cylinderCommon
- Poor connection or damaged wiring at the coilLess often
- Failed ECM ignition driver, least likelyLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and note which cylinder coil 'A' serves.
- Inspect the coil boot, plug wire, and spark plug for cracks, carbon tracking, or fouling.
- Swap the suspect coil with a neighbouring cylinder and see if the fault follows it.
- Check the coil connector and wiring for a poor connection.
- Replace the failed coil, boot, or plug, then clear the code and re-test.
FAQ
Quick answers
Is it safe to drive with P2302?+
For short distances, but a steady misfire can overheat and damage the catalytic converter — especially with a flashing light. Fix it promptly.
Can I just clear P2302?+
It returns within a few drive cycles unless the failing coil, boot, or plug is actually replaced.
Related codes
Often seen with P2302
Read & clear P2302 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