P03FC

Ignition K Control Signal Circuit High

High severity

Ignition K Control Signal Circuit High: the signal voltage is above the expected range. This line drives an ignition coil group; a fault causes misfire on those cylinders.

Common causes

Short to B+
One of the most commonly reported causes for this code — check this first.
high
Typical part cost: $70-550
Connector pins corroded - high contact resistance
Less common, but worth ruling out after the more likely causes.
low
Typical part cost: $70-550
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First things to check

1Confirm the code with a scan tool and check for additional related codes.
2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.

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Related codes

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Frequently asked questions

What does P03FC mean?

P03FC means "Ignition K Control Signal Circuit High". It is a generic OBD-II code that points to a fault in the ignition system or misfire.

What are the most common causes of P03FC?

short to b+; connector pins corroded - high contact resistance; supply wire pinched against b+ source — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.

Can I keep driving with this code?

This code points to a problem that can cause damage or affect safety. Avoid driving and have the vehicle diagnosed promptly. Use the Wrenchify app for a full diagnosis specific to your vehicle.

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