How old are the controllers ? When that happens it usually means software on the board is incompatible with the service tool . You need to upgrade the baseline software to a newer version . I forget what they are up to now ...think ending in AAG ? Be aware that even once you change the chip there are usually a couple of parameters that need changing . Haven't had to do one for a while but last one I did I had a regional guy talk me through the changes over the phone .