P0350 — Ignition Coil Primary/Secondary Circuit Malfunction
Drivable short-term, but fix now to avoid damage.
What P0350 means
This code indicates a fault in an ignition coil's primary or secondary circuit, which the computer detects as an electrical problem in how the coil fires the spark plug. A faulty coil circuit causes misfires, leading to rough running, lost power, and possible catalytic converter damage if left unrepaired. Fixes usually involve replacing the faulty ignition coil or repairing its wiring and connectors.
Common symptoms
- Check engine light is on or flashing
- Engine misfires or runs rough
- Noticeable loss of power
- Hard starting or stalling
- Increased fuel consumption
Common causes
- Faulty ignition coil
- Damaged coil wiring or connector
- Open or shorted primary/secondary circuit
- Worn or fouled spark plug
- Faulty ignition control module or driver (rare)
Typical repair cost
$100 – $400
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0350 code?
Only briefly, and not if the check engine light is flashing. A flashing light means an active misfire that can damage the catalytic converter, so it's safest to stop and get it repaired.
How much does it cost to fix a P0350 code?
Most repairs cost between $100 and $400. Replacing a single coil and spark plug is on the lower end, while wiring repairs or multiple coils can raise the price.
Is a P0350 code serious?
Yes, it can be. Misfires from a bad coil circuit can damage the catalytic converter and leave you with reduced power, so it should be addressed quickly.
Can a bad spark plug trigger a P0350 code?
It can contribute, since a worn or fouled plug stresses the coil. Technicians often inspect both the coil and plugs together when diagnosing this code.