Ignition Coil F Primary Control Circuit/Open
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.
Can I keep driving? Drive as little as possible — the affected cylinder misfires, and a flashing check-engine light warns of converter-damaging misfire.
Real-world scan data
Appears alongside · share of P0356 scans
Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.
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?+
Can I just clear P0356?+
Related codes
Read & clear P0356 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.