The AOD's I know are supposed to have that cable.
I dont know if the AODE needs it or not. Having an electronic valve body an all. Its like in my truck. I have a 4L60E. It is a 700R4 with an electronically controlled valve body. Mechanically they are the same. But the 4L60E version does not have the detent cable like the 700R4 has. Its fully electronic. So if you have an AODE,.. it may not have any need for that cable and if so then this is a pointless avenue to keep working on. There would be something else wrong with the transmission if the problem is indeed with the transmission.

Hurst