Powertrain
Definition only
Lights the check engine lamp
P289C: Cylinder 4 Ion Current Sense Circuit
Standardized SAE J2012 code · P28xx codes
What does P289C mean?
The ECM cannot read a valid ion current signal from cylinder 4. Ion current sensing relies on the spark plug acting as an electrode after combustion.
The code tells you which monitor failed, not which part is broken. Test before replacing parts.
Common causes
- High Ion sense module failed
- Medium Wiring or connector fault
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of P289C on the same make and model first.
P289C in the community
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Describe your P289C problemRelated codes
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- P28A8 Cylinder 7 Ion Current Sense Circuit
- P28AC Cylinder 8 Ion Current Sense Circuit
- P28B0 Cylinder 9 Ion Current Sense Circuit
- P28B4 Cylinder 10 Ion Current Sense Circuit
- P28B8 Cylinder 11 Ion Current Sense Circuit
- P28BC Cylinder 12 Ion Current Sense Circuit