Javier, BMW in successive years changed the round external trans interface serial connector pin count around MY 1989...you can check the ETK to confirm the transistion point as the trans P/N would change accordingly. This change may or may not affect the interface to the 35 pin trans control module. My suggestion is take a picture of the trans control connector...your answer may be in the back of Bentley...I haven't scrutinized it that close...and then number each terminal with say MSPaint.
The resident expert on these transmissions is Kirt Koeller. Here is his contact information: E-mail him the picture and explain your issue. BTW, do you have a 3rd-4th gear shifting issue corresponding to low resistance for what may be solenoid no.4?

Kirt Koeller’s contact info:
Autosports Unlimited
Ask for Kirt Koeller
(800)624-3876 ext 5735 or direct at
(616)748-5735
europetransman@hotmail.com

Be sure to let us know what you find out.