What does code P289F mean?

Q: What does code P289F mean?

Cylinder 4 Ion Current Sense Circuit High. P289F means the engine control module (ECM) has detected an abnormally high voltage on the ion current sense circuit for cylinder 4, which is used to measure combustion quality. The ECM expects a specific voltage range during the ion current measurement window and sees a signal that is consistently above the acceptable threshold.

DTC codes / P28xx · Transmission / P289F

P289FCylinder 4 Ion Current Sense Circuit High

P289F means the engine control module (ECM) has detected an abnormally high voltage on the ion current sense circuit for cylinder 4, which is used to measure combustion quality. The ECM expects a specific voltage range during the ion current measurement window and sees a signal that is consistently above the acceptable threshold.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaTransmission

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.