BMW General Module 4 or GM4 page.
The BMW GM4 is used on the E36 3-series from model year 1994 until the end of production. Also used on the Z3 coupe and roadsters from model year 1997 until end of production. One thing I saw said these modules where made by Hella, but, I think mine is made by United Technologies Automotive.
What does the GM4 module do? It controls interior lighting, central locking (door locks, trunk and fuel filler door), door lock heater, power windows and power sunroof.
The GM4 is located behind the glovebox above the Relay Module 4 (RMIV) and Washer/Wiper Module.
Update 11/15/08 - I got my GM IV module and took the lid off and pictures are to follow.
This module uses 5 relays. Two of them are the familar V23078-C1002-A303 relays, available here, that are also use on the BMW GM3 and GM5 modules. The other three relays are V23072-C1061-A303, available here, that are also used in the BMW GM3 module.
I have numbered the relays and will refer to them when I figure out what each relay does. I'm fairly confident that RLY1 and RLY2 are for the front window and RLY3, 4 and 5 are for the door locks. For rear window control the GM4 connects to the Relay Module 4 or RMIV. This module contains a pair of V23078-C1002-A303 relays as well.
BMW General Module II (GM2) Page
BMW General Module III (GM3) Page
BMW General Module V (GM5) Page
V23072-C1061-A303 Relays Diagram
V23078-C1002-A303 Relays Diagram
