Ok, the 12pin diag plug was disconnected and opened itself... wires fell out. This is the signal mapping I know, and here is a link to what it should look like from the outside: http://jenniskens.livedsl.nl/Technical/Tips/Pics/Diag%2012pin%20plug.jpg  (no pic from internals however) These colors seem different. I check the schematics form a 1988 and compared to what I have and you sent:

Pinning 928 (female) Wiring loom color Description
P12 connector
----------------------- --------------- ---------
1     Black                                 Term15 Vdd ignition (connects to V21 on the CEB)
2     Brown+Brown                 Ground (2 different wires welded in the same pin, connects to chassis gnd)
3     Blue/Yellow                     Speed/ engine rpm (connects to pin 13 on the EZK)
4     Green                               Knock (connects to pin 14 on the EZK)
5     Red                                   Permanent 12v (connects to V22 on the CEB)
9     White                                Hall Signal (connects to pin 22 on the EZK)
10    White+White                 K-line (one wire comes from LH pos. 12 and the other comes from EZK pos. 1)
11    Black+Brown/White     Check engine (one wire from LH pos. 22 and the other comes from EZK pos. 31)
12    White+White                  L-line (one wire comes from LH pos. 16 and the other comes from EZK pos. 7)

These signals can all be traced and are confirmed now. Should not be too hard to verify using an Ohm-meter.
http://jenniskens.livedsl.nl/Technical/Tips/4/MyTip421.htm  here you will find the EZK and LH pin numbers
http://jenniskens.livedsl.nl/Technical/Tips/6/MyTip600.htm  is about CEB connector numbering.
 

regards

Theo Jenniskens

1992 928GTS Midnight Blue