What does code P28A8 mean?

Q: What does code P28A8 mean?

Cylinder 7 Ion Current Sense Circuit. P28A8 indicates that the engine control module has detected an abnormal signal on the ion current sense circuit for cylinder 7, which is used to measure combustion quality through ionization current across the spark plug gap. The computer expects a specific voltage or current pattern during each combustion event and flags this code when the signal falls outside the expected range.

DTC codes / P28xx · Transmission / P28A8

P28A8Cylinder 7 Ion Current Sense Circuit

P28A8 indicates that the engine control module has detected an abnormal signal on the ion current sense circuit for cylinder 7, which is used to measure combustion quality through ionization current across the spark plug gap. The computer expects a specific voltage or current pattern during each combustion event and flags this code when the signal falls outside the expected range.

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.