roadsterlife

Hi all - I have been having some issues with my 2014 Cayenne's sound system. I bought it CPO last year, so fortunately it has warranty but the dealer has unable to isolate the issue. Back in January, I noticed that music was periodically cutting out. I brought it in to the dealer for that and the transfer case, and they replaced the PCM as a result.

However, the issues persisted and if anything, got worse over time to the point where there was no sound at all. Additionally, it would have a weird issue where I wouldn't be able to switch sources from Tuner to Media and vice versa. The dealer replaced the PCM again earlier this month. Not surprising, the issue has returned again. I will be bringing it back again, but I am curious if anyone has had a similar issue and if the fix came from somewhere else, perhaps from an issue with the amplifier system or bad ground? Any help would be greatly appreciated.

RAudi Driver

When I worked on my car, my PCM went into that mode where I couldn't change the modes. It was my amplifier. Had to reset it by disconnecting the battery for a few seconds. You may have some water damage back in that area causing your issue. I didn't but know of others that have.

nsully

You may want to investigate the condition of the amp. for moisture intrusion.
I believe the sunroof drains(rear), when clogged, will allow water to leak/run down on the amplifier.
The amp is located behind and below the luggage compartment passenger side access panel.
Pop it out and check to see if you can feel any moisture.
Good Luck!

RAudi Driver

I have a write up I can make to get to that amp. I took pictures o the steps needed and which step to do first. I can possibly make some time tonight to do that. I have some time of so maybe I'll post up all these DIY's that are sitting in my computer.

roadsterlife

That would be really appreciated. While I think this is something my dealer should do (since it is under CPO warranty) I think it would be helpful to know how to get there. I popped the cover off when I got home from work, but had no idea where to even look within there as it is kind of tight. Thank you guys for commenting and helping with this.

roadsterlife

Just an update - ended up being a blown amplifier. No signs of water damage and the sunroof drains are working fine, but either way, replaced under warranty and seems to be working well now.

deilenberger

THANKS for reporting back what it was - that makes this thread hugely valuable to someone facing the same problem in the future!

Graeme Stacey

My 996 C4S PCM cuts out consistently after 12-15 minutes. It goes 'pop' and dark, then after a few minutes the white logo reboot screen appears and usually the message System Error: CD changer, Phone, Amplifier not available. If i turn the car off and back on the PCS starts up again fine... for another 12-15 minutes. My gut says I've got a component in the amplifier somewhere - a capacitor or resistor failed or a dry joint. Its 15 years old after all. Any thoughts?

Update - so i removed the cigarette lighter to plug in my phone charger. The PCM stays on. It stays on every time now. Here's what I conclude (I welcome confirmation from anyone who understands PCM technology). The cigarette lighter must have been pushed in just enough to draw a current but not enough to pop out/was sticking so could not pop out. Either the system detected a rogue current being drawn, or an over-heat occurred. I've been told that if the system detects too high a current being drawn from the battery it is programmed to sacrifice non-essential systems like PCM to protect the safety systems reliant on the battery. I conclude that this is what was happening, consistently, because of the cigarette lighter. That could have been expensive - bullet dodged.

Tom M

You can send it to Becker for repair if you want to retain the stock system.

deilenberger

Graeme, welcome to Rennlist. I believe you've posted this in the wrong forum.. you might consider posting it in a 996-911 forum.
https://rennlist.com/forums/996-forum-60/

Also when you do post it there - please include the year of your 996. There are differences in the PCM's for various years.

Graeme Stacey

Thanks I'll take a look there.