Welcome to the forum. I've searched many times for the owners handbook PDF but have never found one. The locking/freewheel front hubs was an option so I assume yours doesn't have this fitted. The SJ's don't have a central differential so don't use the 4wd until your driving on a loose or slippery surface. If you drive on tarmac in 4wd you can/will damage the drivetrain.
2005 Grand Vitara MT 1600se.