Does MK3/4 control sound?
 

Hi guys

I’m hoping to find a DIY fix for a very odd problem with my sound system. Every so often the sound switches off for no good reason, I can still switch tracks and use sat nav but no sound. Sometimes switching the engine off and on solves the problem. The dealer is unable to do diagnose the problem since muting is intermittent.

I’ve got MKIII in my X5 2001. From the other posts I learned that it could be either MKIII which blew up when the battery was changed or DSP (don’t know what that is). I’m think about buying a second hand MKIII on eBay but I’m not sure whether I’m replacing the right part.

Could somebody confirm whether MKIII controls sound or it’s something else?

The MK3 is for Navigation, check to see if your radio tuner is still ok, and check fuse if necessary.

A bad MKIII unit can definitely display the symptoms with the audio system that you've described. I know this because my own MKIII unit also does this periodically. Downgrading (O/S v22.1 or lower) then upgrading the firmware has helped but periodically I still get the same issue.

If that doesn't fix it and you have to get a new nav unit, by ALL MEANS get the MKIV instead of the crappy MKIII. They are plug-and-play compatible and you will have far better reliability (not to mention cool features!).

Good luck!

Thanks Wolf!

I'm still a bit confused - some people say MK III could be the root of the problem with sound whereas others say MK is a GPS thing only. I wonder if there is a simple diagram that shows how things are connected GPS-CD changer-speakers?

MKIV costs more on ebay then III, just want to make sure I'm not throwing money away

No diagram, but the CD changer connects to the MKIII via the cable terminated with the burgundy colored connector. They are inter-related components and, as I've experienced, a malfunction with the GPS unit can result in audio drops (usually temporary until the car is restarted or the GPS system reboots spontaneously - another sign of a faulty MKIII unit).

Probably the best way to test your system is borrow an MKIII or MKIV from a buddy. Just be sure to let your navigation system turn completely off (90 seconds or until red light goes off) and remove the negative cable from your battery before disconnecting AND reconnecting any navigation unit or you might be buying TWO navigation units!

You may also have luck purchasing MKIV units from bimmernav.com. Some guys are reporting mixed results with their Ebay purchases (incorrect country coding, incompatible MOST host-interface, etc). Contrary to some other posts, he is still selling them at:

http://www.bimmernav.com/store/catal...-item-123.html

Good luck!