Problem with electronic transmissoin;reverse doesn't work,sth's broken in ELECTRONIC GEARBOX?

Hi everybody, I took it to a local dealer, but nobody was able to fix it... so I have to do it myself! (somehow?). DOES ANYBODY HAVE TECHNICAL DESCRIPTION, TECHNICAL DRAWINGS TO THE GEARBOX OR TRANSMISSION SYSTEM PLEASE? IT'S ELECTRONIC, KIA CARNIVAL 2000. thanks a lot;sth's wrong with reverse, GEARBOX?