What does code P289C mean?

Q: What does code P289C mean?

Cylinder 4 Ion Current Sense Circuit. P289C indicates that the engine control module has detected an abnormal signal on the ion current sense circuit for cylinder 4, which is used to monitor combustion quality and detect misfire. The circuit typically consists of a spark plug with an integrated ion sensor or a dedicated ionization module that measures the electrical conductivity of the combustion gases immediately after the spark event.

DTC codes / P28xx · Transmission / P289C

P289CCylinder 4 Ion Current Sense Circuit

P289C indicates that the engine control module has detected an abnormal signal on the ion current sense circuit for cylinder 4, which is used to monitor combustion quality and detect misfire. The circuit typically consists of a spark plug with an integrated ion sensor or a dedicated ionization module that measures the electrical conductivity of the combustion gases immediately after the spark event.

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.