Ignition Coil Primary/Secondary Circuit Malfunction
There’s a problem with the ignition coil circuit.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The engine's control module (ECM) isn't seeing the right signals from the ignition coil, which can cause misfires or rough running.
What the computer is actually seeing
The ECM monitors the voltage and resistance in the ignition coil circuit. If it detects voltage below 0.5V or above 5V at the coil's connectors when it should be firing, it will trigger a fault code.
What a healthy reading looks like
The ignition coil should show 0.5 to 2 ohms of primary resistance and about 10k to 15k ohms of secondary resistance when tested with a multimeter.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the wiring and connectors for the ignition coil. Look for frayed wires or corrosion.
- 22. Measure the primary and secondary resistance of the ignition coil with a multimeter. Replace the coil if readings are out of the normal range.
- 33. Inspect the ground connections for the ignition system, ensuring they are clean and secure.
- 44. If the coil is okay, check for faults in the ECM by verifying proper voltage and ground at the ignition coil connector. If absent or out of specs, check wiring back to the ECM.
Common causes
- Faulty ignition coil
- Wiring issues or damaged connectors in the ignition system
- Faulty ECM
- Corrosion or bad ground connections
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not ideal; you may experience misfires and poor performance, so fix it as soon as possible.
Will this code come back after clearing?
If the ignition coil circuit fault is fixed, the code should not return.
Why does this code sometimes pair with other codes?
Other misfire or ignition system codes can trigger off the same electric or mechanical fault in the system.
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