What does code P28B5 mean?

Q: What does code P28B5 mean?

Cylinder 10 Ion Current Sense Circuit Range/Performance. P28B5 indicates that the powertrain control module (PCM) has detected an out-of-range or performance fault in the ion current sense circuit for cylinder 10. The PCM uses this circuit to measure ionization current at the spark plug gap after combustion, which helps detect misfire, knock, and combustion quality; when the signal falls outside expected limits, the code is stored.

DTC codes / P28xx · Transmission / P28B5

P28B5Cylinder 10 Ion Current Sense Circuit Range/Performance

P28B5 indicates that the powertrain control module (PCM) has detected an out-of-range or performance fault in the ion current sense circuit for cylinder 10. The PCM uses this circuit to measure ionization current at the spark plug gap after combustion, which helps detect misfire, knock, and combustion quality; when the signal falls outside expected limits, the code is stored.

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.