how speedometr works on x5 ,2003 4,4i
 

cable or electronicly from from AI chip ?

Electronically calculated through wheel speed sensors by DSP then translated to the cluster via bus line.

so the amp determines the speed signal? how? Here is how it really works...


The left rear wheel speed sensor is used to calculate speedometer. This signal is sent to the abs control unit via hardwire. The abs control unit be it ASC, or DSC sends this signal TW via hardwire to the instrument cluster. The instrument cluster determines the actual road speed via coding data stored. The instrument cluster generates "speed signal A" and outputs this via k-bus/i-bus.

Not even close for both of you. There is a hamster involved in determining the speed. His heart rate is calculated and output via an complex German formula which gives speed in kph. Now the question is, where is he located.

OOPS! I meant DSC not DSP........ (corrected by killcrap) But I think the Meister hit the nail on the head for the german way of thinking. (that is about how the DMTL system works in all honesty!)

Firstly thank you !..it's good answer ,I'm renesance man was looking for a cable ( haha potentially located behing dash/b ets)
no offence what DSC and ASC means ( I'm proved dumm)
2) where in left rear wheele it's located . Diagram is not needed ..in words would be OK I have my imagination
Many thanks again

I get the feeling you are trying to disconnect your speedometer / odometer?