P2331
Ignition Coil K Primary Control Circuit High
Ignition system
Generic OBD-II
Medium
What it means
P2331 means the PCM detected high voltage on the primary control circuit for ignition coil "K." The primary side isn't switching as commanded — usually an open or a short to power in the wiring, or a coil/driver fault — so the affected cylinder may misfire, causing rough running and reduced power. On engines with many coils, "K" refers to that specific coil's control circuit.
Medium
Can I keep driving? Usually yes short-term, but the cylinder may misfire; a sustained misfire can damage the catalytic converter, so repair it soon.
Common symptoms
What you'll notice
- Check-engine light on (may flash during an active misfire)
- Rough idle and engine shake
- Misfire or hesitation from the affected cylinder
- Reduced power and fuel economy
Common causes
Most likely first
- Open or short-to-power in the coil 'K' primary control wiring/connectorLikely
- Faulty ignition coil 'K'Common
- Poor or corroded connector at the coilCommon
- Failed coil driver inside the PCM/ignition moduleLess often
How to diagnose & fix
Work through it in order
- Identify the cylinder coil 'K' serves and inspect its connector and control wiring for opens or shorts to power.
- Swap or bench-test the suspect coil against a known-good one.
- Check the coil's power, ground, and control-circuit continuity.
- Repair the wiring or replace the faulty coil.
- Clear the code and confirm the misfire is gone on a road test.
FAQ
Quick answers
Is it safe to drive with P2331?+
Briefly, but a misfiring cylinder can damage the catalytic converter and worsens over time. Repair it promptly, especially if the light is flashing.
Can I just clear P2331?+
It returns as soon as the coil circuit faults again. Fix the wiring or coil first.
Related codes
Often seen with P2331
Read & clear P2331 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