P0351 on Ford: How to Diagnose & Fix
Ignition Coil A Primary/Secondary Circuit Malfunction
2 Ford models · 2 documented issues · $120-$900 repair
P0351 on Ford by model: symptoms, diagnosis and fix
Explorers (especially the Sport and Platinum) with the twin-turbocharged 3.5L EcoBoost are widely reported to develop cylinder misfires, a flashing check-engine light, rough idle and a loss of power that owners frequently chase by replacing ignition coils and spark plugs. The turbocharged, high-heat environment is hard on plugs; the factory Motorcraft SP-534 plug wears its ground strap prematurely and the Explorer's 3.5L EcoBoost is direct-injection only (no port injection), so intake-valve carbon buildup aggravates misfires. A recurring root cause traced on the forums is broken/seized exhaust manifold studs that create a vacuum-style exhaust leak right at the cylinder head, which repeatedly destroys coils and triggers misfire codes until the bolts are addressed. Ford never issued a recall for the manifold studs.
Common Symptoms
- Flashing or steady check-engine light
- Cylinder misfire / rough idle
- Loss of power or hesitation under boost
- Ticking/exhaust-leak noise on cold start
- Repeated coil failures after replacement
How to Fix
Replace all six spark plugs with the updated Motorcraft SP-580 (supersedes SP-534, pre-gapped to ~0.032 in) and renew failed coil-on-plug units; do plugs as a set on or before the 60,000-100,000 mi interval (severe-duty/towing service much sooner). If misfires recur after coil/plug replacement, inspect for broken exhaust manifold studs/bolts and an exhaust leak at the head and replace the studs. Adding a catch can and the updated SP-580 plug reduces fouling on these direct-injection-only engines.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Ignition CoilCross-refGN10237
Fitment confirmed against the ShowMeTheParts catalog for this vehicle's year and engine.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (3)
A failed coil sets a cylinder-specific misfire (P0301-P0308) and often a matching coil-circuit code (P0351-P0358), causing a shake at idle, hesitation, and a flashing check-engine light.
Common Symptoms
- Cylinder-specific misfire, rough idle, engine shake
- Hesitation/bog on acceleration
- Flashing check-engine light
- Fuel smell from exhaust, slight economy drop
How to Fix
Confirm the bad coil by swapping it to an adjacent cylinder and seeing if the misfire follows. Replace the failed coil (and its spark plug), apply dielectric grease to the boot to seal out moisture. Consider a full coil/plug set at high mileage.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Ignition CoilCross-ref0221504704
Bosch Engine Management Sensors 0221504704. Fitment confirmed against the ShowMeTheParts catalog for this vehicle's year and engine.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (2)
P0351 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0351 mean on a Ford?
P0351 stands for "Ignition Coil A Primary/Secondary Circuit Malfunction." P0351 indicates the engine computer found a fault in the primary or secondary circuit of ignition coil 'A' (typically the coil for cylinder 1 or the first coil in the firing system). The PCM monitors the coil's control circuit, and when the electrical feedback doesn't match what it expects during firing, it sets this code. Because the coil creates the high-voltage spark, this often causes a misfire, rough idle, hesitation, or loss of power. It is a circuit/component fault for one specific coil rather than a general engine problem. On Ford it is documented across 2 models: Explorer, F-150.
What are the most common causes of P0351?
The most common causes of P0351 are: Failed or weak ignition coil, Damaged or corroded coil connector or pigtail, Broken or shorted wiring in the coil control circuit, Loss of power feed or ground to the coil, Worn or fouled spark plug overloading the coil, Failed coil driver inside the PCM/ECM. The specific cause varies by vehicle.
How much does it cost to fix P0351 on a Ford?
Published repair estimates on Ford range from $120 to $900 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0351 on a different make?
View P0351 across all makes →Join 700+ subscribers following Au7o for vehicle insights and updates.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.