Toyota iQ 1.0 1KR-FE 89663-74034 Firmware
A catalog overview of Toyota iQ 1.0 1KR-FE firmware identified as 89663-74034.bin.
89663-74034 is a Toyota engine-control calibration identifier associated in this catalog with the iQ 1.0 and its 1KR-FE petrol engine. The Toyota 89663 part-number family is used for engine control software, so this file is best understood as an engine ECU calibration.
What the engine ECU controls
The engine ECU uses sensor inputs to manage functions such as fuel injection and ignition timing. These controls affect how the 1.0-litre engine starts, idles and responds to the accelerator, as well as its fuel consumption and emissions. Those are general engine-management functions, not documented changes specific to 89663-74034.
The filename IQ 1.0 1KRFE 89663-74034.bin identifies the vehicle, engine and calibration number. It does not name a modified feature or establish what changed in this particular revision. The related catalog entry repeats the calibration identifier without adding a variant label.