P2311
Ignition Coil D Secondary Circuit
Ignition system
Generic OBD-II
Medium
What it means
P2311 indicates a fault in the secondary (high-voltage output) circuit of ignition coil "D" — the side that delivers spark to the plug. A weak or breaking-down secondary circuit means that cylinder gets little or no spark, causing a misfire, rough running, and lost power. The cause is usually the coil itself, the spark plug, or the connection between them.
Medium
Can I keep driving? Usually yes short-term, but the cylinder may misfire; running a misfire for long risks catalytic-converter damage, so fix it soon.
Common symptoms
What you'll notice
- Check-engine light on (may flash during an active misfire)
- Rough idle and engine shake
- Misfire, hesitation, or stumble under load
- Reduced power and fuel economy
Common causes
Most likely first
- Faulty ignition coil 'D' (secondary winding breakdown)Likely
- Worn or fouled spark plug on that cylinderCommon
- Damaged coil boot, spark-plug wire, or connectionCommon
- Carbon tracking/arcing at the coil or plugLess often
- Poor connector or wiring at the coilLess often
How to diagnose & fix
Work through it in order
- Identify the cylinder coil 'D' serves; inspect the plug, boot, and coil for wear or arcing.
- Swap the coil (and plug) with a known-good one to see if the fault follows the part.
- Replace a failed coil boot, spark-plug wire, or fouled plug.
- Check the coil connector and wiring.
- Clear the code and confirm the misfire clears.
FAQ
Quick answers
Is it safe to drive with P2311?+
Short term, but a misfire can damage the catalytic converter. Repair the coil or plug promptly, especially if the light flashes.
Can I just clear P2311?+
It comes back once the secondary circuit fails again. Replace the failing coil or plug first.
Related codes
Often seen with P2311
Read & clear P2311 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