As mentioned in my above posts, I noticed that the sat antenna connection is not great since the connector is tiny and brittle, I eliminated the reboot issue by improvising a strain relief of sorts on the sat antenna. Since that job, no more reboots.
The sat antenna provides info to PCM for gps, etc. if that becomes sporadic, I can definitely see coders having checks in code to check signal, and if signal becomes unstable, pcm starts thinking issues, and reboots itself.
Worked for me.

 

ATTENTION TO ALL!!
Talked to my dealership multiple time about PCM reboot that started yesterday evening.
Bob in Louisville (Nice guy in service) stated "XM Sat Radio put out an update that is causing ALL Porsche cars with PCM to have this reboot ever 2 min"!! I won't bore you with to many detail, but from what I know about how XM sends updates, I believe it!!!
My indi shop in Lex KY is also getting lots of calls... THIS IS GOING TO BE A MESS!! Cut off your XM antennas before it's to late!!! JUST JOKING .....
BTW.. My first post.... and I just got my first Panamera this month (2012 4S with 55k miles)... Best car ever made so far!! (if I can keep XM out of my system )...


Good luck to all!!!

 

Happened to me today on the way home from work!!!!! This is crazy!!!!

 

2011 Panamera Base, today PCM started shutting off while car running. Display goes blank, then get Porsche splash screen, then liability screen. Stays on for about 2.5 minutes and "reboots" again. Drove home about 30 minutes and like clockwork every 2+ minutes. I input active navigation to my house just to see and it retains the active navigation upon reboot. An enigma wrapped in a riddle. 78K miles, latest PCM software and maps done in 2019. Nothing is connected (USB, phone, etc.). Maybe XM... I hope! and not the hard drive or PCU.

 

Happened to me first time today. Anyone know when Sirus will send a fix?

Initially thought was Bluetooth from my iPhone, as they had a software update last night.

 

This just started happening to my Panamera yesterday only 43k miles. A little relieved to see I’m not alone and it sounds like a XM radio issue. ( although there are 10 different potential solutions I have read in threads today)But I’m not sure what my course of action should be now. Wait for XM to send a fix, go to the dealer? Or do a hard reset?

 

Check in Rennlist, there’s a step by step on the 911 and Cayenne board. Yes, looks like hard reset, so save your favorites, then contact / website Sirius and they will send a fresh signal.

 

I have a 2011 Turbo Cayenne and sure enough this morning it started shutting off every couple of minutes. I just got off the phone with Serious and I think I got the issue resolved. It took 3 tries but it seems to be OK now. I had to do a PCM reboot as if the car is handed over to a new owner. I think the reason it took 3 times is because the system was shutting itself off every 2 minutes before it completed the task. Now I have to do all new reprogramming including the phone.
I was asked to disconnect my Bluetooth when I started this process. Hopefully this will help all others who were effected by this update. Serious representative was aware of the Porsche dilemma.

 

Thank you, will the pcm reset be enough or do I also need to contact XM radio to coordinate
the effort with something on their end?

 

I am not sure if it is necessary to have the Sirius resend the signal but when I called them at 1-866-687-4213 they did. I think they might have done it actually couple of times. At the end of my session with them they acknowledged that the update effected all Porsche vehicles. My other car ML-350 was not effected at all. Go figure ...

 

Thank you everyone for your help. The pcm turning off every two minutes has been resolved by calling XM radio (Mr Z provided in this thread) systemically requesting a new signal.( 1 minute call) and resetting the PCM as suggested above. I’ve included a link that helped me complete this in a couple of minutes
thanks everyone for your help !!

 

ok, for all those older 2010 panamera owners, the hard reset doesn't work on our cars however after going through everything posted from other members with newer models what I did was " I called Sirius XM and had them completely cancel the service from my radio" wait about 20 to 30 minutes and then do the hard reset. Then your unit will finally work as normal, in our older models the trick is to call Sirius to have them remove the service completely, then proceed to do the hard reset and then your PCM will go back to normal

 

hmmm.
I'm receiving Sirius XM for free because the previous owner allowed me to use his subscription. I wonder if we can just wait until Sirius sends a new update to fix the issue?
How about just sending the refresh signal to my car?

 

I much appreciate the PCM Reset instructions!. This did resolved my Panny PCM rebooting issue

 

As I saw here, many of us has had the same problem as mine. All of purposals I tried and all was a failure.
I fixed very easy ( and forget rebooting for 10’sec to the option meny to porshe pcm restart etc because none of them doesnt work as you know).
pcm itself has a platter below ( Hardisc) so all you have to do is to change it ( not all pcm or to buy new pcm). Just the platte of hardisc and its fixed. Thats it.