Shift on the Fly System

OUTLINE OF SHIFT ON THE FLY SYSTEM
The shift on the fly system switches between 2 wheel drive (2WD) and 4 wheel drive (4WD) electrically by driver's pressing the 4WD switch (push button type) on instrument panel.
This system controls below operations. (Shifting between "4H" and "4L" must be performed by transfer control lever on the floor.)
1. Shifting the transfer front output gear (Connecting to, and disconnecting from, front propeller shaft by motor actuator).
2. Retrial of shifting the transfer front output gear.
3. Connecting front wheels to, and disconnecting them from, the front axles by vacuum actuator.
4. Indicator on instrument panel.
5. 4WD out signal to other Electronic Hydraulic Control Unit.