Ignition Coil H Primary Control Circuit/Open
What it means
P0358 means the ECM detected an open or fault in the primary control circuit of ignition coil "H" (the eighth coil in firing sequence). Without a proper drive signal that coil can't fire its cylinder, so the engine typically misfires, runs rough, and loses power. The cause is usually the coil, its connector, or the primary control wiring.
Can I keep driving? Driveable but rough — the cylinder on coil H is likely misfiring, so limit driving to avoid catalytic-converter damage.
Real-world scan data
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 if the cylinder is misfiring)
- Rough idle and engine shake
- Misfire, hesitation, and reduced power
- Possible hard starting
Common causes
Most likely first
- Failed ignition coil HLikely
- Open or shorted coil primary control wireCommon
- Loose or corroded connector at the coilCommon
- Fault in the ignition driver / ECM output for that coilLess often
How to diagnose & fix
Work through it in order
- Scan and read freeze-frame data to confirm the fault is coil H's primary control circuit.
- Inspect the coil connector and wiring for an open, short, or corrosion.
- Swap coil H with a known-good coil to see if the fault follows the coil.
- Check the primary control wire back to the driver/ECM for continuity and the driver's output.
- Replace the coil if it is faulty; repair the wiring or driver as found. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0358?+
Can I just clear P0358?+
Related codes
Read & clear P0358 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.