Intermittant sound and system error

[declanka]

Hi my C4S (2003) has an intermittent issue with the console, sound and system errors, there are a few after market items the main one being and system to use ipod/phone which seems to have replaced the cd changer. My independent Porsche repair specialist has tested and looked at the wiring, replaced the Amp and the phone unit, bypassed the phone unit and the issue is still there. Today as an example

 

I had to drive 60 KM , heavy motorway traffic outbound, Intermittant sound from start of journey but only quiet for short period second or two getting longer after about 45 minutes driving. Occassionally system error popped up “No phone, CD changer”. It also was intermittent when trying to play a CD on the console. On the return journey after 2 hours parked and switched off it was also intermittent more frequently and for longer say 10 secs. The console also twice went dark and seemed to repower up.

Has anyone any ides what the issue might be or how to find it?

Declan

 

[987_RDC]

The phone/CD changer plug in the back on the radio is pretty straight forward. I would think either ignition switch needs replacement (causes electrical gremlins) or swap out the radio with one from eBay. (can get coding from this forum)

[declanka]

Thanks is the Radio a separate component (tuner etc) or part of the console?

[Loren]

Do you have a CDR-23 or a NAV package like PCM?

[Richard Hamilton]

I assume you have PCM.  As you must have worked out, there are 3 external units - Amplifier, CD Changer, and Telephone.  They are connected to the head unit by the MOST (fibre optic )loop.  If any one of the units in the loop fails, all communication and sound signals are lost.  Assuming the fibre optic cables are intact, and you have replaced the amp and bypassed the phone module, that only leaves the CD Changer - or the aftermarket iPod adapter.  I would try bypassing it, and see what happens.  Or if it is a Dension unit, try switching it to service mode.

[987_RDC]

Ah sorry I thought you had base CD radio, not PCM.

[declanka]

Yes its a PCM type, will try as suggested, Thanks

[wvicary]

Verify that the cooling fan in the PCM unit is functioning correctly. They easily overheat and it cause odd issues.