Toyota Lexus Firmware 89663-37B90

89663-37B90 is a Toyota or Lexus firmware calibration identifier. The 89663 part-number family is associated with engine control software, so this entry tentatively belongs to an engine control module calibration.

An engine control module uses sensor readings to manage engine operation, including functions such as fuel delivery and ignition timing. That general role does not establish what this particular calibration changes or which vehicle it fits.