I have looked over several publication's wiring diagrams and have not seen this combination of wire colors (even tho' some are obscured in the photo)going to one location. The box is definately of Japanese origin (their tin alloy), as is the connector. Yellow colored insulation USUALLY denotes circuits intended for instruments. The black/red is noted as grounding circuit for the ECM and diagnostic connector and that light green/yellow could be for the vacuum switching valve for the fuel press regulator.
My guess is that this box is the main relay with a timer for the warning lamps...Cal