Hi, my 4wd in my stagea doesn't want to work with or without the 50/50 button pressed, sometimes there is both the 4wd and abs lamp on but I don't know how to check the codes, where does the ecu even sit? But the 4wd doesn't work even when the light isn't on when I spin the front wheel the axel to the gearbox does rotate, the oil for the attesa is there. I don't really know how to check if the pump is working or not. Help would me appreciated thanks