What does code P231F mean?

DTC codes / P23xx · Ignition system and misfire / P231F

P231FCylinder 12 Air-Fuel Ratio Imbalance Adjustment At Limit During Balance

P231F indicates that the powertrain control module (PCM) has detected an air-fuel ratio imbalance on cylinder 12 that is severe enough to reach the adjustment limit during a balance test. The computer tried to equalize power output across all cylinders and found that cylinder 12 cannot be corrected any further, meaning it is contributing unevenly to engine operation.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaIgnition system and misfire

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.