03 Audi A8 D3 MMI cutting out issue
 

First time I have used a forum or posted on one so bear with me if I have got protocol wrong. I would appreciate any help on the following problem with my A8 4.2Ltr Quattro 2003 MMI system:

I have just bought the car and the MMI works fine when the engine is off. When swithed on with engine not running it seems to work perfectly in all modes ( except in car audi phone - I haven't got a sim card for it yet), BUT when the engine is running, een if the car is not moving, it clicks and cuts out turning off the CD if playing, resetting the sat nav, cutting the radio out. The cutout. drop outs are triggered by an irregular but frequent ( 1 second to say 1 minute frequency) static type electronic click. If it was an older car it almost sounds like a suppression problem. Clicking and crackling away. It happens on all frequencies on the radio.

It doesn't make the car unusable but is very annoying if you want to use the stanav or radio/CD. My car is also fitted with what looks like a ipod link unit with plugs and cable connection which I think is a Dension gateway unit probably fitted from new but I can't be sure.

Any one else got this problem? Can anyone offer a solution if they had the problem?

It sounds like something is taking down the MOST bus which uses fiber optic cable to connect the entire entertainment system of the vehicle. The only real way to find out is to one, take it to a dealer, or two find someone with a VAG COM and do a ring break test on it to see what is taking down the system.

Thanks for taking to time to reply to my query Sincityaudi, its very much appreciated. I guess I will take it down to the main dealer for a ring break test as you suggest. I generally don't like taking intermittant oddball problems on older cars to Audi main dealers they are usually disinterested.

I drove the car in driving rain yesterday and it seemed a little worse than normal with the radio clicking out every few seconds with a 'static' sounding type click or mutiplecclicks each time. Some times it stayed silent for a many seconds ( up to one minute after the clicks before sound appeared again for maybe a few seconds or a few minutes before doing it again. It doesn't appear to relate to road bumps or suspension movement. I've deliberately tried driving over bumps to see if this evokes the cutout but it doesn't. Yesterday the screen and sat nav seemed to hold itself on OK throughout these radio cut outs.....

Thanks Again very much appreciated

Does the screen on the center of the dash ever cut out? If it doesn't then you probably just need an amplifier (which isn't cheap), but if the screen is cutting out then I would definitely say you have a MOST Bus module taking down the system.

Hi - The screen doesn't shut down but the information on it is sometime lost in that the image remains. For example when the radio cuts out the screen clears and the radio needs a few seconds where it seems to be 'thinking' to refind to find the station. same with sat nav. It drops out then has to refind the destination. The screen is OK though its still lit and doesn't flicker but can breifly lose image. When you say the amp do you mean the bose amplifier under the left hand boot cover...I think its there....Is this a known fault or could it just be a bit of damp/loose connection etc. can I do anything to fix it other than replace? Can a specialist repair it? and why does it still work with no problem when the car engine isn't running? Does this stack up?...sorry to ask so many questions...I really appreciate your kind help...Thanks in anticipation Shaun

Hi - The screen doesn't shut down but the information on it is sometime lost in that the image remains. For example when the radio cuts out the screen clears and the radio needs a few seconds where it seems to be 'thinking' to refind to find the station. same with sat nav. It drops out then has to refind the destination. The screen is OK though its still lit and doesn't flicker but can breifly lose image. When you say the amp do you mean the bose amplifier under the left hand boot cover...I think its there....Is this a known fault or could it just be a bit of damp/loose connection etc. can I do anything to fix it other than replace? Can a specialist repair it? and why does it still work with no problem when the car engine isn't running? Does this stack up?...sorry to ask so many questions...I really appreciate your kind help...Thanks in anticipation Shaun

:)Hi - The screen doesn't shut down but the information on it is sometime lost in that the image remains. For example when the radio cuts out the screen clears and the radio needs a few seconds where it seems to be 'thinking' to refind to find the station. same with sat nav. It drops out then has to refind the destination. The screen is OK though its still lit and doesn't flicker but can breifly lose image. When you say the amp do you mean the bose amplifier under the left hand boot cover...I think its there....Is this a known fault or could it just be a bit of damp/loose connection etc. can I do anything to fix it other than replace? Can a specialist repair it? and why does it still work with no problem when the car engine isn't running? Does this stack up?...sorry to ask so many questions...I really appreciate your kind help...Thanks in anticipation Shaun