The speed signal might be your problem if your GPS signal is weak.
eg: if you are driving around a part of London where the you are on narrow streets and srrounded by high rise buildings, you can easily have GPS reception problems - if you have speed pulse connected, the nav keeps on working when it has no GPS signal. But no speed pulse = it stops working.
What PDOP and what satellite S/N signals were you getting? These figures determine GPS accuracy and tell us if your antenna is good.
Your software is very old, the current version is 3-1/63
It's worth updating. You will get split-screen mode and vastly improved graphics.
You'll need the BMW OS CD and the Key CD.
Both are here:
GREN.RU - Прошивки для Нави блоков БМВ
Any OS CD from V22 and newer has 3-1/63 on it.
When getting ready to burn the image, please check the image is Mode2/Form1 before burning - a Mk3 will read Mode2/Form1 CDs but will crash when reading Mode1
Tip: ImgBurn is a vey good reliable and free burning program (
The Official ImgBurn Website)
The wiring diagram of the nav system is in the retrofit instructions. Ideally, you want to use the DF_AVL (or AVR) speed pulse signal (L or R front wheel speed pulses). Have a look at the wiring diagram, The supplementary wiring harness is what is used to connect the speed pulse on the retrofit loom, but because you used an original loom, the speed pulse wire should be in the main part of the loom.
Post some photos or describe the unused connectors and wires (with their wire colours) of the loom you used, and we'll tell you what wire is the speed pulse wire.