Instrument cluster connection is for speed pulse, correct.

Dead-reckoning is the term used to navigate when there is no GPS reception. The nav uses compass, speed, and forwards/backwards to update the position calculation.

Navcoder is here:
http://www.xoutpost.com/navigation-sy...-released.html

I guess your problem is that the nav is coded for Mono. Remove nav, look at label. Does it say BMWM01S on the label anywhere? If so, it is Mono (Colour is BMWC01S). NavCoder can change Mono to Colour, BMW service department cannot :-)