P0351 Ford Explorer
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 Explorer 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 Explorer.
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 Explorer.
Common Causes on Ford Explorer
- 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 Explorer
Ford coil-on-plug units are inexpensive — when replacing one, consider replacing all of them as preventive maintenance if they have over 80k miles.