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.).

 

TSB is Technical Support Bulletin

 

I called my dealer today. He said it has happened in the past (2014) and Porsche is aware of it. He took my info and said they will call me with the solution. He said the update is sent via the satellite link on the car. I asked if they can send the fix the same way and he said he had no idea but would let me know. Mine was fine yesterday and fubared today. Patience, I guess. Got to love these damn computers we drive around in.

 

Same thing here in North Alabama with my 2013 Cayenne Diesel. Same exact issue.
I did send an email to the local dealer, awaiting response. I'll post here if/when I get it.

 

Thanks all who posted. Same here, PCM was fine when I drove into work Wednesday now rebooting like the rest when I drove home today.

 

1. Press and hold the INFO button until the system reboots
2. Press CAR
3. Press OPTION
4. Select SET PCM SYSTEM
5. Select RESET PCM
6. Select VEHICLE HANDOVER
7. Select YES
8. Select YES

That will resolve your issue. Please know that you will have to reset all of your stations and relearn your phone for Bluetooth purposes after this is completed.

 

My 2011 Cayenne started doing this yesterday, leading me to this thread. It's every 2 minutes like clockwork. Odd thing is it won't even stay off. If it's an XM issue I'll believe it but I just don't see how it could corrupt the system to this degree.

 

2015 Boxster, with Sirius XM. Just started this week shutting off and on. Last night (this morning) at 3:00 AM the damn radio just turned on all by itself, loud! Woke me from a deep sleep. So what do we do about this?

 

2016 991.1 S with Sirius, identical issue - reboots every couple of minutes, and starts up by itself if turned off!

Possible fix below (did actions together so unfortunately cannot identify which procedure worked, but suspect fuse removal may be unnecessary if PCM is wiped out as described and Sirius XM refreshed since that was identified to be the cause).

Removed fuses for PCM B10 on driver side, also A UL, A LL, B7 and C10 on passenger side. Left out for 5-10 minutes.

Reset PCM with complete erase using "vehicle handover" option in PCM. Erases presets, device connections, everything.

This last step also erases Sirius/XM account info (and presets), so then sent radio refresh to radio using the self-help online tool on Sirius XM website (Website had radio ID code saved in profile so no need to provide it again).

So far PCM has not rebooted again in the 120 second cycle it was exhibiting. We'll see if fix persists.

 

Same problem with my 2016 Macan S. Started rebooting every 2-3 minutes yesterday. I have a Sirius subscription.

Called my dealer, who informed me that this is a nationwide issue. PCNA is aware of the problem, but no fix available yet.

 

Dealer followed up - advice is to do a PCM hard reset/handover as zinca4 did. Fuse removal is not necessary.

Instructions:
1. Press and hold PCM>>Info button for approximately 10 seconds until the PCM reboots.
2. Immediately select the following from the PCM CAR>>OPTION>>Set PCM System>>Reset PCM>>Vehicle Handover>>Yes>>Yes

 

Good thread! Mine just started doing this today, so I will try the reset and let you know.

 

Slightly different order of doing things - if one doesn't work, try the other

 

Tried both methods, no joy. I’ll call my buddies at a local shop to see how they do it.

 

From Rennlist user: Vehicle Handover.
Press and hold the PCM >> Info button for approximately 10 seconds until the PCM reboots. - Immediately select the following from the PCM: CAR >> OPTION >>Set PCM System >>Reset PCM >> Vehicle Handover >> Yes >> Yes"

i performed the Vehicle handover and it fixed the reboot issue. Now I only have XM Channel 1 Preview. Spent over an hour on chat and they couldn't get a signal to my car. I got a message on my phone (they sent me a refresh text) saying I had exceeded the maximum number of activation signals in 24 hours. The chat guy said he only had permission to send one signal to me (bizarre). Then as I was returning from my car he chatted he was leaving because I didn't respond and he assumed the problem was resolved. I'll try again tomorrow. At least it's not rebooting. The Vehicle handover does remove all your navigation favorites (bizarre), and removes your set radio stations. I work in IT, we call this a single point of failure. lol