What does code P28BF mean?

Q: What does code P28BF mean?

Cylinder 12 Ion Current Sense Circuit High. P28BF indicates that the engine control module (ECM) has detected an abnormally high voltage on the ion current sense circuit for cylinder 12, which is part of the ignition system used to monitor combustion quality. The ECM expects the ion current signal to stay within a specific voltage range during each combustion event, and a high reading means the circuit is either seeing voltage it should not or the sensing element is not providing the expected feedback.

DTC codes / P28xx · Transmission / P28BF

P28BFCylinder 12 Ion Current Sense Circuit High

P28BF indicates that the engine control module (ECM) has detected an abnormally high voltage on the ion current sense circuit for cylinder 12, which is part of the ignition system used to monitor combustion quality. The ECM expects the ion current signal to stay within a specific voltage range during each combustion event, and a high reading means the circuit is either seeing voltage it should not or the sensing element is not providing the expected feedback.

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.