Beru pencil coil mystery

[MSIMARD]

Hello.
I have Beru coils and need to know how to wire them with an IEX and M48.
I haven't been able to find out much about them, any thoughts would be greatly appreciated.

They are 4 wire and used in Porsche Cayenne and Carerra GT. They seem to be a self igniting 'smart' coil. Beru has a flyer which might hold some clues: http://www.beru.com/download/produkte/fachaufsatz_zsp_e.pdf

A Porsche wiring diagram shows:
Pin1: 1.5mm Brown (main ground?)
Pin2: 1.0mm Brown/Blk (?)
Pin3: 1.5mm Red/Ylw (12v+)
Pin4: 0.5mm unique color per cylinder

#s 1 and 3 seem likely to be the main power ground and supply. #4 does seem to be a trigger input but the question is how to wire to IEX? And what is #2?
Brown is universally GND in Porsche wiring.