What does code P289D mean?

Q: What does code P289D mean?

Cylinder 4 Ion Current Sense Circuit Range/Performance. P289D indicates that the engine control module has detected an out-of-range or erratic signal from the ion current sense circuit for cylinder 4, which is used to monitor combustion quality and detect misfire. The circuit typically measures ionization current across the spark plug gap after ignition, and this code sets when the voltage or current feedback falls outside the expected range for the current operating conditions.

DTC codes / P28xx · Transmission / P289D

P289DCylinder 4 Ion Current Sense Circuit Range/Performance

P289D indicates that the engine control module has detected an out-of-range or erratic signal from the ion current sense circuit for cylinder 4, which is used to monitor combustion quality and detect misfire. The circuit typically measures ionization current across the spark plug gap after ignition, and this code sets when the voltage or current feedback falls outside the expected range for the current operating conditions.

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.