P0356
Ignition Coil F Primary Control Circuit/Open
Ignition / coil
Generic OBD-II
High
What it means
P0356 means the engine computer detected a fault or open in the primary control circuit of ignition coil F (usually cylinder 6). That cylinder loses spark and misfires, so the engine runs rough and loses power. It won't normally cause a full no-start on a multi-coil engine, but a sustained misfire can damage the catalytic converter, so fix it promptly.
High
Can I keep driving? Drive as little as possible — the affected cylinder misfires, and a flashing check-engine light warns of converter-damaging misfire.
Common symptoms
What you'll notice
- Check-engine light on (may flash under an active misfire)
- Misfire, rough idle, and shaking
- Reduced power and hesitation
- Poor fuel economy
Common causes
Most likely first
- Failed ignition coil F (typically cylinder 6)Likely
- Open or shorted primary control wiring to the coilCommon
- Loose or corroded coil connectorCommon
- Fault in the coil driver inside the engine control moduleLess often
- Worn or fouled spark plug at that cylinder (secondary side)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the code is coil F's primary circuit.
- Inspect the coil connector and control wiring for damage, corrosion, or an open.
- Swap coil F with a neighbouring coil to see if the fault follows the coil.
- Test the coil's primary control signal from the ECM; replace the coil if it's open or shorted.
- Check the spark plug at that cylinder. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0356?+
No — a dead coil means one cylinder isn't firing, which wastes fuel and can overheat the catalytic converter. Repair it quickly.
Can I just clear P0356?+
It will clear briefly but returns as soon as the coil circuit fault reappears.
Related codes
Often seen with P0356
Read & clear P0356 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