Lexus NX300h 89663-78191 Firmware
A catalog reference for Lexus NX300h 2.5 2AR-FXE hybrid firmware identified as 89663-78191.
89663-78191 is a firmware catalog identifier associated with the Lexus NX300h and its 2.5-liter 2AR-FXE hybrid powertrain. The 89663 part-number family is associated with Toyota and Lexus engine control software, making an engine-control application plausible for this entry.
In a hybrid vehicle, the engine control system manages combustion-engine operation and works with the hybrid control system to coordinate the engine with the electric drivetrain. That general role does not establish what this particular calibration changes or which control module carries it.
Catalog identification
The listed file, Lexus NX300h 2.5 2ARFXE hybrid 89663-78191.bin, identifies the vehicle, engine and calibration number. It does not name a stock or modified variant, a specific feature, or a service bulletin. The exact function and vehicle applicability of this revision therefore remain unconfirmed.