Toyota 89665-0C231 Firmware: Calibration Catalog Reference
A concise reference to Toyota firmware identifier 89665-0C231 and its control-module part-number family.
Toyota 89665-0C231 belongs to the 89665 part-number family associated with engine control module calibrations. The association with engine control is tentative because the complete identifier alone does not establish its exact application.
What the calibration family controls
An engine control module uses calibration data to manage engine operation, including fuel delivery, ignition timing and emissions-related functions. The specific behavior controlled or changed by 89665-0C231 cannot be identified reliably from the part number alone.
The complete identifier is important when comparing service or calibration records. A similar 89665 prefix indicates a related part-number family, not necessarily the same vehicle application or software revision.