P0351 Ford F-150
Ignition Coil A Primary/Secondary Circuit Malfunction · Powertrain Code · High · Repair: Easy
What is P0351?
The ignition coil for cylinder 1 has an electrical fault.
When the Ford F-150 triggers code P0351 (ignition coil a primary/secondary circuit malfunction), it typically points to an issue in the powertrain system. This is a high severity code, so address it promptly to avoid further damage or safety concerns. Below you'll find the most common causes, symptoms, and repair options specific to the Ford F-150.
This repair is rated easy, meaning basic tools, no lift needed.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Ford F-150.
Common Causes on Ford F-150
- Failed ignition coil on cylinder 1
- PCM coil driver circuit failure (rare)
- Corroded coil connector or damaged wiring
- Short in the coil-on-plug boot from spark plug blowout (5.4L Triton issue, less common on newer engines)
Symptoms
- Check engine light
- Misfire on cylinder 1
- Rough idle
- Reduced power
Notes for Ford F-150
Ford coil-on-plug units are inexpensive — when replacing one, consider replacing all of them as preventive maintenance if they have over 80k miles.