P0351 — Ignition Coil "A" Primary/Secondary Circuit Malfunction (Cylinder 1)
An electrical fault is detected in both the primary and the secondary circuit of ignition coil A (cylinder 1). The ECU cannot drive the coil correctly, so the cylinder served by coil A misfires or does not fire at all. Causes: an open or shorted primary control wire, an internal coil winding fault, a failed igniter/driver, or wiring or connector damage at the coil.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Ignition coil
- Ignition coil wiring
- Ecu ignition driver
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Coil primary winding open or shorted
- Wiring or connector fault
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Related codes
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.