What does code P289E mean?

Q: What does code P289E mean?

Cylinder 4 Ion Current Sense Circuit Low. P289E indicates that the engine control module has detected an abnormally low voltage on the ion current sense circuit for cylinder 4, which is used to measure combustion quality. The circuit typically monitors the small current that flows through the spark plug gap after ignition to detect misfire and knock, and a low signal means the module cannot reliably assess cylinder 4's combustion.

DTC codes / P28xx · Transmission / P289E

P289ECylinder 4 Ion Current Sense Circuit Low

P289E indicates that the engine control module has detected an abnormally low voltage on the ion current sense circuit for cylinder 4, which is used to measure combustion quality. The circuit typically monitors the small current that flows through the spark plug gap after ignition to detect misfire and knock, and a low signal means the module cannot reliably assess cylinder 4's combustion.

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.