Toyota 89663-08374 Engine Control Module Firmware

Toyota 89663-08374 is an engine control module calibration, listed as the updated calibration 896630837400 in Toyota service bulletin T-SB-0049-18. The engine control module manages engine operation by processing sensor information and directing functions such as fuel delivery and ignition timing. Its calibration determines how those controls respond under different operating conditions.

What this calibration identifies

The complete calibration identifier connects 89663-08374 to the engine control module, rather than another Toyota controller with a similar-looking number. The bulletin identifies it as an updated calibration. The service record does not establish which specific engine-control behavior changed in this revision.

T-SB-0049-18 covers certain 2017–2018 Highlander and Sienna models and the 2018 Camry. That is the scope of the bulletin, not proof that this calibration applies to every vehicle listed. A vehicle’s existing calibration and service information are needed to establish the applicable revision.