E30 Zone

Does an M20 2.5 automatic use a 173(motronic) ECU same as a manual?
Also I assume a switchable auto box uses a relay?where is it located?

please double check there may be different versions but i think this is the ecu number
0 261 200 381 (motronic) bosch, and there is another in the trunk it's for the autobox ecu don't know the number of that.