Surf 4wd light flashing beeping

[Camfitz30]

I try to engage 4wd but the light flashes and beeps , it's a 2lte wiring loom with a 1kz motor in it, but it's running a Manuel injection pump. I thought it was the speed sensor not working at first but repaired that but still not working. Hard to explain but hope you guys catch my drift haha