i dont know of any, the ecus are interchanageable other than slight map data change
the powerfc is direct plug in unit for both car models with no physical wire or code changes
a known difference i can think is s1 afm is 4 wires and s2 afm is 3 wires
the changes for this are done in the engine looom wiring and not the wiring loom at the socket side
that is, the s1 ecu doesnt handle the afm ground differently to the s2 ecu
another one i can think of is next to the TPS the s1 has two plugs, one is disconnected always
on the s2 i think both are connected. again i think those changes are done on the lcoal loom and dont have anything to do with the ecu side