My friend who was talking about the EWS reprogramming was talking about a hack. He still has to sift through the module and see if its possible, but he's confidant it can be done. I dont really care much either way, but it would increase accessibility if he could make it work!
So, now we're pretty much down to two things:
- the differences between the voltage regulators in the MS42 and MS43
- pin 52 on module 3 (the secondary air pump valve)
After this, we're pretty much done. I'm out of ideas on both though.
Also, I went through the parts diagrams on realoem.com to verify that all of the parts are the same between the M52TU and M54. It looks like 03/2003 is the conservative cut off for compatibility between parts on the two engines. Before 03/2003, pretty much the only differences in engine sensors, relays, servos, motors, etc, were limited to a delete of the suction jet pump, and the addition of DBW.
The pdf file comparing all of the part numbers between the two engine types is up in the first post of this thread.