What does code P28AC mean?

Q: What does code P28AC mean?

Cylinder 8 Ion Current Sense Circuit. P28AC indicates that the engine control module has detected a fault in the ion current sense circuit for cylinder number 8, which is used to measure combustion quality and detect misfires. The circuit typically consists of a spark plug with an integrated ion sensor, a sense module, and wiring to the ECM; the code sets when the ECM sees an abnormal voltage or current return from that circuit.

DTC codes / P28xx · Transmission / P28AC

P28ACCylinder 8 Ion Current Sense Circuit

P28AC indicates that the engine control module has detected a fault in the ion current sense circuit for cylinder number 8, which is used to measure combustion quality and detect misfires. The circuit typically consists of a spark plug with an integrated ion sensor, a sense module, and wiring to the ECM; the code sets when the ECM sees an abnormal voltage or current return from that circuit.

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.