Pccm plus woes - any suggestions please

Hi currently have a 2003 turbo with Bose and most installed the pccm no sound pulled the fibre optic at the CD player to check and no red light shining through cable this point think I have messed fibre cable so pull out pccm and pop pcm back in works straight away check fibre optics at cd changer again and red light back to the head units - on pcm the fibre optic light in on in a constant state when I plug the pccm back up the fibre optic light from the control unit is cycling one second on about 30 seconds off when it is on for that one second I get sound What have I done wrong? the fact that it is regularly cycling makes me think it is something I have done or not done or is the control unit faulty? any suggestions please? many thanks

Is the MOST bridge connected on the CD changer?

How are you connecting the head unit to the MOST? I've it working using and xtronics MOST to AUX adapter? I did notice this was a little "moody"..once it was working it was good..but sometimes despite clicking in...there was learly sometjing it didnt like with connection and no sound...resolved after a few disconnect/reconnect attempts.

do you not replace the cd changer with a loop? didn't think the cd changer could be used with PCCM

With the PCCM+ there should be no need for a third party adapter - everything is included in the kit.

Hi thanks for the replies Yes I did replace the cd changer with the loop, just meant with the original pcm 2.0 unit in and remove the loop the fibre optic loop can see the light coming through, not with the pccm Have contacted porsche dealers and are suggesting I need to ground the amp, but I was under the impression this was only with pcm 1.0 and dsp not pcm and Bose, there is no wire at 17 to remove and replace with an earth as per pdf instructions on line Anyone any ideas? With most I thought it was basically plug and play for the pccm Thanks again for the replies

I cant see why, when you are effectively replacing like for like you would need to ground the amp ? The big selling point is plug and play, remove the cd changer and add the loop. I think esendia or Demort may be able to help as they both seem familiar with the system

Yeah that was the big draw was the plug and play - just can't understand it - everything else working fine on it except sound (have tried the can amp change as well which shouldn't need to be done as mine has most but tried anyway) at this stage I'm beginning to think the most converter is faulty or maybe even the whole unit 🤷"â™‚️

I have to say .. i'm not a fan of these units .. for something that's supposed to be plug and play at a rather extortionate cost they tend to cause a lot of issues . The over amplified signal .. ie lvl 3 and too loud seems to be fixed by the adaptor .. i cant confirm as i haven't used it and it depends on the system . Most systems seem to work ok .. its the non most that has issues . Some images below of the instructions for the amp earth wire .. you need to have these option codes for this to be applicable .. again i've not fitted this earth wire so am unsure of what happens if its not fitted .. but these are the instructions . The original classic radios were not very good .. these don't seem to be much better .. some work out of the box .. but from the amount of posts here and my own experiences some don't . I've fitted both types .. and i've removed both types after customer complaints !

I missed the last image for getting the amp to work . Obviously this is for applicable vehicles only .

Thanks for the replies folks See I'm totally confused because my car had pcm 2.0 with Bose and most The instructions say you only need to ground if pcm 1 and m680 Then show how to do it with 18 pin plug and dsp in it - but my 18 pin plug has only 3 cables I have attached the pictures the opc sent me

If you don't have that option code then you don't need to earth the amp .. I will say a Most cable ( orange ) if bent more than the size of a coke can it wont work .. a kink in these cables stops data transmission .

I thought it was something like that but actually have two old pcm 2.0 here (one with dodgy screen) and both work perfectly - it's really strange

I'm sorry to ask this but if anyone has one of these with most could you pull the loop at the cd changer and see if the red optical light cycles on and off or stays on constantly - many thanks

Thread resurrection... Hello - did the original poster resolve this problem please? I am working with a friend on his turbo that has the same issue. Head unit fitted and working, but no sound. System is BOSE plus fibre. The optical signal is cycling as described above. The optical cable is in good condition with clear ability for light to get through. The amp doesn't have the need to be earthed, but we tried that anyway to no avail. Also - on the chance that its an amp problem, can anyone recommend a place to send it to so this can be confirmed and repaired? Many thanks, Graham.