no sound, speakers intermittent

[renntechno]

I was having this issue, where the  PCM 2.1 was showing the error message of navigation unavailable and no sound from the system. I figured it was the PCM, because everyone has said that these fail over time and get that message. I was getting sound intermittently whenever I disconnected the battery or pulled the fuses. So, after I replaced the HU, everything was working fine. There must have been a power draw and the battery died after leaving the CTT parked for 4 days in cold weather. I recharged the battery and the HU is working fine, but the speakers are cutting out, similar to the issue I was having before replacing the PCM 2.1. I thought it was the PCM's fault, but apparently, it's something else. Any ideas?

[Guest]

If you are in single digit F cold weather and park outside like me, there is an issue with the sound cutting out.  I experience the same with my '08 Cayenne S.  Had previously replaced the HU with a refurbished one.  Works great in temps in the teens and above.  As for the specific cause, sorry, can't help you there.  I am fairly certain it is the amp causing the problem. Being located in the right rear panel, it gets the brunt of the cold. 

[renntechno]

I changed out the amplifier and this didn't help. I will now check the connections to all 14 speakers to look for a short. Apparently, these speakers will all cut out even if therre is a short on just one component. I assume that includes the DVD Sat-Nav player under the passenger seat as well. I did have water ingress on the floorboards recently, which I remedied by pulling the seats and carpets out and drying everything as well as clearing the drain holes under the wheel cowlings. Perhaps there is residual moisture in the DVD player?  Does anyone have the wiring diagram for the PCM 2.1 sound system?