vyper developments,
well done for finding the fault.
Abs ecu modules are in fact different, there are different colour multiplugs and sockets also the plug sizes are different so I dont think you can physically connect the wrong type unit.
they are the same size but have some metal pins inserted in the loom plug that line up with holes in the ecu socket. you can fit the wrong plug to the ecu only by drilling out these pins. which would be stupid as nothing will work and you'll probably damage the ecu.