Toyota Firmware 89663-28A91: Calibration Catalog Reference
A concise reference to Toyota firmware identifier 89663-28A91 and its engine control calibration family.
89663-28A91 is a Toyota calibration identifier in the 89663 part-number family, which is associated with engine control software. Its tentative association is with an engine control module, or ECM, rather than a separately identified vehicle system.
An ECM uses software calibrations to manage engine operation, including fuel delivery and ignition timing. The complete identifier distinguishes this calibration from other entries in the same family, but the identifier alone does not establish the exact vehicle application or the changes made in this revision.