Ignition Coil A Primary/Secondary Circuit Malfunction
Common Symptoms
- Check engine light on
- Cylinder 1 misfire
- Rough idle
- Loss of power
Most Likely Root Causes
- Faulty ignition coil cylinder 1
- Open or short in coil wiring
- PCM coil driver failure
- Corroded coil connector
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Severity / Derate Risk
High if CEL flashing.
Component Location
Ignition coil on top of spark plug, cylinder 1.
Manufacturer Notes
Coil A = cylinder 1 on most vehicles. Swap coil first — fastest diagnosis.
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