Hi all, spent a couple of days trying to fix this after work, so thought I'd share. It may help you if your Jimny is stuck in 4wd or 2wd with the little green light on the dashboard flashing away at you. After a day on the lanes, Little Jim decided to get stuck in 4wd. I did drive it home the 114 miles which is not ideal but we made it. Having taken some advice from forum members, and my friendly mechanic (remotely of course which makes it a little harder!), I set to work. Luckily we've had some decent weather. Just a note - you may only need to mess with the transfer box if it won't change on command. Any way, although I am fairly convinced that in the end it was the motor on the transfer box which I swapped from a spare, these are the steps taken, just need to fit manual hubs now as decided the vacuum system is a faff when things go wrong. This is a 2007 with push button selector.
1. Disconnect battery.
2. To get it out of 4wd and back into 2wd, the motor / actuator was removed and I manually put the box into 2wd by turning the mechanism anti-clockwise. Remove this bit:
This was a spare box I had, you don't have to remove from the car! Then you need to turn this gear bit anti clockwise:
3. Vacuum pipes need to be disconnected and blocked off. Cover the old metal pipes to avoid water ingress. Just need to tidy these up:
4. Block the vacuum both on the engine and the pipe leading into the old system. Again, still need to tidy mine:
5. Next bridge the connector under the battery to fool the system:
5: Refit the motor / actuator on the transfer box.
6: Reconnect the battery, should recognize everything in current position.
Now, there should be no flashing light on the dash, and it should move between 2wd and 4wd on the buttons. Just remember, although the front prop turns, the hubs may be unlocked (mine are currently stuck on, but that is fine to drive still in 2wd mode).
Hope this helps, will update with further progress (hopefully an awning, manual hubs, 2nd battery and maybe a winch!)