Ignition and misfire
P0351 — Ignition Coil A Primary/Secondary Circuit
The ECU detected a fault in the primary or secondary circuit of ignition coil A (usually cylinder 1). The coil may not produce a strong enough spark, which leads to misfire.
Common causes
- Failed ignition coil
- Damaged coil connector or wiring
- Worn spark plug overloading the coil
- Failed ignition driver or control module (rare)
- Moisture in the coil boot
Symptoms
- Rough idle and misfire
- Loss of power
- Hard starting
- Flashing or steady check engine light
How to check
- Inspect the coil connector and wiring
- Swap coil A with another cylinder's coil and see whether the code moves
- Check the spark plug condition
- Test coil resistance and supply voltage
Can you keep driving?
Avoid long trips. A misfiring cylinder can damage the catalytic converter, so repair it soon.
Related codes
Frequently asked questions
- What does P0351 mean?
- Ignition coil A has an electrical problem in its primary or secondary circuit.
- Is P0351 the same as P0301?
- Not exactly. P0351 is a coil circuit fault; P0301 is a detected misfire in cylinder 1, which a bad coil can cause.
General reference information. It does not replace a diagnosis on your own vehicle. The same code can have different causes depending on make, model year and engine; check the manufacturer's documentation or ask a technician with a scan tool.