P0351 - Ignition Coil A Primary/Secondary Circuit
The ECM detected a primary or secondary circuit fault for ignition coil A.
Code first. Confirm symptoms and checks before pricing parts.
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Common Next Steps
Turn the code into the next check.
Check coil boots, carbon tracking, and whether the miss follows a swap.
Inspect gap, fouling, wear, oil, coolant, and plug-well condition.
Move to injector balance, pulse, or leak-down checks if the misfire stays.
Use compression or leak-down testing when spark and fuel checks do not move the fault.
Code Overview
The ECM detected a primary or secondary circuit fault for ignition coil A.
Common Causes
- Failed ignition coil
- Coil wiring issue
- Poor connector fit or terminal tension problem
- PCM driver issue (rare)
Diagnostic Steps
- Swap the coil if the design allows and see whether the fault follows
- Inspect the coil connector, pins, and boot for heat or carbon tracking
- Check for companion misfire codes and verify power and ground at the coil
Likely Repairs & Cost Guides
Confirm the repair path before pricing parts.
Estimator-ready next step after the fault path is confirmed.
Estimator-ready next step after the fault path is confirmed.
Related OBD Codes
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Next Steps
Move from code to checks, then estimate.