Pajero GDI stalls when put into reverse

I have a problem with my automatic Pajero GDI. It stalls when put into reverse, the only thing you can do to stop it stalling is to put your foot down on the accelerator but this can be difficult some times when pulling out of parking spots. I have had sensors checked, control units checked, fuel pumps checked, nothing changes. I'm told it is a control unit problem, the computer not reading or relearning properly, apparently a common problem that develops with age. Can the control unit be replaced to fix this problem? No one has given me a solution to this problem and it has been going on for 2 years now. The engine gets adjusted and it is alright for a for a month then it starts again. I now have to decide whether I can get this problem fixed or just cut my losses and get a new car. Being in Namibia also makes things more difficult as the mechanics here don't seem to now how to fix this problem only that the problem exists. It is a Japanese import Pajero.