P0351: Ignition Coil A Primary/Secondary Circuit Malfunction
Can you still drive? Not recommended for extended driving. A misfiring cylinder can overheat the catalytic converter. Replace the coil as soon as possible.
What Does P0351 Mean?
Code P0351 indicates that the ECM has detected an electrical fault in the ignition coil circuit for cylinder 1 (coil A). This could be an open circuit, short circuit, or abnormal resistance in the primary or secondary winding of the coil. A failed coil means cylinder 1 will not fire, causing a misfire on that cylinder.
Need to read your codes?
An OBD-II scanner lets you read and clear diagnostic trouble codes from your vehicle's computer. Most scanners work with any car made after 1996.
Browse OBD-II Scanners on AmazonCommon Causes
- Failed ignition coil
- Damaged coil connector or wiring
- Faulty coil driver circuit in ECM
- Corroded spark plug causing coil overload
- Short in coil primary or secondary winding
Symptoms
- Check engine light on or flashing
- Engine misfire on cylinder 1
- Rough idle
- Loss of power
- Engine vibration
Diagnostic Steps
- 1Measure ignition coil primary resistance (typically 0.4-2 ohms) and secondary resistance (6,000-15,000 ohms)
- 2Swap coil A with another cylinder coil to determine if the fault follows the coil
- 3Check coil connector for power, ground, and trigger signal
- 4Inspect spark plug for excessive wear or carbon tracking
- 5Check coil boot for carbon tracking or tears
- 6Monitor misfire counters with scan tool after coil swap
Recommended Parts & Tools
Estimated Repair Cost
| Type | Estimated Cost |
|---|---|
| Total Repair Cost Range | $30 - $250 |
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Chat with AI About P0351Commonly Affected Vehicles
Related Recalls
1 Active Recall — 2026 Ford F-150
The following NHTSA safety recalls have been issued for this vehicle. Contact your dealer to check if your vehicle is affected.
ELECTRICAL SYSTEM: INTEGRATED TRAILER BRAKE CONTROL
Ford Motor Company (Ford) is recalling certain 2021-2026 F-150, 2022-2026 F-250 SD, F-350 SD, F-450 SD, F-550 SD, Maverick, 2024-2026 Ranger, 2023-2026 F-600 SD, 2022-2027 Lincoln Navigator, Expedition, and 2026 E-Transit vehicles. When towing a trailer, the integrated trailer module (ITRM) may lose communication with the vehicle, possibly causing a loss of brake and turn signal lights, or a loss of brake function. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 108, " Lamps, Reflective Devices, and Associated Equipment."
Remedy: The integrated trailer module software will be updated by a dealer, or through an over-the-air (OTA) update, free of charge. Owner notification letters are expected to be mailed March 17, 2026. Owners may contact Ford customer service at 1-866-436-7332. Ford's number for this recall is 26C10. Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning March 17, 2026.
Data provided by the National Highway Traffic Safety Administration (NHTSA).
Frequently Asked Questions
Should I replace all ignition coils at once?
It is not strictly necessary but many mechanics recommend it, especially if the vehicle has high mileage. If one coil has failed, others are likely nearing the end of their lifespan as well.
How long do ignition coils last?
Ignition coils typically last 80,000 to 100,000 miles, but they can fail earlier due to heat, vibration, or spark plug issues. Using worn spark plugs increases the voltage demand on coils and shortens their life.
Community Fix Reports
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