Alright, I scanned the codes, they came back as:
P1738 Pressure Control Solenoid "E" Electrical
P1743 Pressure Control Solenoid "C" Electrical
P1746 Transmission Control Module Output Stage
and P0743, Which I couldn't find anything for.

Again it was raining when this happened. Could it simply be the connections? Or am I looking at something serious?

This also happened to me...I believe the codes are false. Mine was corroded connectors at the transmission. There are two plugs one near the top and one on the side connected to a square box. Unplug those and spray the connectors with WD-40 or it you want it to last longer use ACF-50.

It fixed mine. Those two plugs are hanging close to the road and are susceptible to corrosion.

This link should work...read at the end.
http://www.xoutpost.com/bmw-sav-foru...fe-prompt.html

Sounds good. I'm going to throw it on a buddy's lift today or tomorrow and have a look.