Toyota Firmware 89663-0KM10-A: Calibration Catalog Reference

89663-0KM10-A is listed in the Toyota firmware catalog alongside the related identifier 89663-0KM10. The 89663 part-number family is associated with engine control software, so an engine-control application is plausible, but the exact controller and vehicle application remain tentative.

What the identifier indicates

Engine control software generally manages functions such as fuel delivery, ignition or injection timing, and emissions-related operation. Those are roles of the controller family, not confirmed changes made by this particular calibration.

The related catalog name contains no vehicle, controller description, or stock or modified variant label. It therefore does not establish a specific fitment or a named behavior for the -A entry.