What does code P28B2 mean?

Q: What does code P28B2 mean?

Cylinder 9 Ion Current Sense Circuit Low. P28B2 indicates that the engine control module has detected an abnormally low voltage on the ion current sense circuit for cylinder 9, which is used to measure combustion quality through ionization current. The circuit is part of the ion sensing ignition system, and a low signal typically points to a fault in the sensor, wiring, or spark plug electrode rather than a simple misfire.

DTC codes / P28xx · Transmission / P28B2

P28B2Cylinder 9 Ion Current Sense Circuit Low

P28B2 indicates that the engine control module has detected an abnormally low voltage on the ion current sense circuit for cylinder 9, which is used to measure combustion quality through ionization current. The circuit is part of the ion sensing ignition system, and a low signal typically points to a fault in the sensor, wiring, or spark plug electrode rather than a simple misfire.

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.