Cayenne S PCM Wiring Diagram

[cooldudeoli]

Hello Everyone,

I had the dreaded PCM problem (blank screen no sound) so I sent my PCM off to be repaired and it got returned today with the screen working except I have no sound still. It has a fault saying that SAT NAV/CD Changer/Telephone/Amplifier cannot be used when I turn it on. I rang the audio company and they said the likely problem is with my fibre optic cable being damaged. I pulled the PCM out, checked all the wiring behind carefully and there are no breaks/kinks, I also took the amplifier out of the boot and that looks in working order. My next move is to trace the fibre optic cable and see which components it goes to after the PCM. If someone has a diagram, or knows of where the fibre optic cables go to so I can check that would be great. Any advice appreciated.

[Loren]

Exact model and year of your car please?

[cooldudeoli]

Hi Loren,

Its a Cayenne S 4.5 2005 Model

Many Thanks

Oliver

[Loren]

There are two fiber optic connectors on the back of the PCM.

H1 is fiber optic signals IN

H2 is fiber optic signals OUT

Where the cables go will depend on the options in your car.

[mudman2]

On 05 I would make a bet on the amp

[rizzo]

I'm in agreement with mudman2.

My 04S has developed the intermittent "no sound" phenomenon too. After one or two restarts or sitting overnight, everything is back to normal.

Some research on this forum has shown similar issues and most of them pointed to the amp. One contributor found that the fuse on his unit was loose. Shoved the fuse all the way in and never had the problem again.

If nothing had changed on the car (impact or disassembly) I'd have to wonder why a fiber optic cable would go bad.

$0.02

:cheers:

On 05 I would make a bet on the amp

[RFM]

Check the fuse on the back of the PCM first, if no avail, do a reprogram with a PIWIS tool.