P28C0

Ion Sense Module Supply Voltage Circuit

Moderate severity

The ECM detects a generic fault on the supply voltage circuit of the ion sense module. The module can no longer reliably bias the spark plug for ion current measurement.

Common causes

Module supply rail interrupted
One of the most commonly reported causes for this code — check this first.
high
Typical part cost: $110-660
Wiring or connector fault
A plausible cause — test and verify before replacing parts.
medium
Typical part cost: $110-660
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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 P28C0 mean?

P28C0 means "Ion Sense Module Supply Voltage Circuit". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.

What are the most common causes of P28C0?

module supply rail interrupted; wiring or connector fault — 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?

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.

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