navigation mk4 connectors

Hi, navigation mk4 computer unit has two connectors: red and blue. what is red one for?
i unplugged it and nav dispaly and radio was wroking fine still. I have 05 bmw x5 4.4.

Thanks,

m

see if this helps

http://www.m5board.com/vbulletin/e39...ple-plugs.html

thanks, it says that red one is for wheel sensors. Why would a nav. computer need wheel sensor input?

need more info on this. Anybody?

beat me..... maybe needs to know which direction car goes?....