My PCM keeps rebooting
 

Started happening today. I started the car and as normal, the USB is "loading" and the bluetooh finds my phone. Then after 2 mins or so, it reboots and seems to do this every 2 minutes. Dealer is aware and they shocked me cuz they said my loaner is a Panamera. I never got a Porsche when my 997 Turbo went in for anyting. Is this a new Porsche wide "deal"?

very common in the Cayenne

I have had a few odd reboots.

UPDATE

Problem fixed. Shut off engine and restart seemed to take care of the problem.

Yesterday, my Pana Turbo started rebooting the PCM every few minutes. The sound would quit with a "tick" and the screen would go blank. Then the white screen with Porsche logo would reappear, the phone would re-sync, and everything would go back to normal ... for about two or three minutes (sometime less) ... rinse and repeat. This happened all day with no change every time I got in the car.

I called my really good dealer service guys and they said that my car (mfg late Jan 2010) should probably already have updated software, but they would check and call me back.

Today, everything is back to normal. No problems of any kind. It's like the PCM module overheard me talking to the service guys and decided to get back on the wagon, or something.

Just a guess on my part, but I think the re-boots might have had something to do with using the "Mix" menu for storing stations from AM, FM, and SAT on the same screen. The car had been flawless, but I only discovered the "Mix" station screen over the weekend and started using it.

When the reboots were happening, the station that was playing when I started the car would come back into tune. I then would re-select a station via the "Mix" memory buttons and get the station I wanted. After the re-boot, the station from starting the car would come back. I eventually regressed to selecting stations by pushing the "Tuner" button to cycle through to select the "AM1" or "FM1" or "SAT1" screens where I would then touch-screen the station I wanted.

At one point, I had every group (AM, FM, SAT) set to "Mix". Pushing the "Tuner" button would kind of confuse me since it seemed to sometimes go to "Mix" and sometimes not.

Maybe it got the PCM confused, too???

the problem is a bad altonator there is a recall on some panameras after they changed it the pcm worked fine no more reboots.

I had the same issues and recently had the alternator recall done. No problems since, but I am watching carefully.

My Panny T is too new to need the alternator recall (late Jan 2010 build). The PCNA Atlanta tech center told my dealer to re-flash the PCM modules with current software (which it should have had already). The dealer techs saw a "gateway" fault code and PCNA wanted more info from me as to when and under what conditions the re-boots were happening as well as what kind of phone I had paired to the Bluetooth phone feature. I have an iPhone 3G (approved), just like some of the dealer personnel who tested their phones with my PCM to try to re-create the problem. Much head scratching.

So, ... I have the car back after 3 days (2010 911 C4S loaner!!) and we'll see if the problem comes back.

Samething with me problem stopped after alternator recal was fixed. Also make sure anybody with an early car has the software upgraded for the problem with the remote start key loosing code from time to time. despite these small issues I still love the pan turbo

My PCM re-booting issues are gone for the moment. After my dealer re-flashed the firmware, it seems to have settled down. PCNA wants to replace the "control unit" anyway because the re-flash took over twice as long as it should have taken to load the code and that makes them suspicious of its integrity. So, I'll take the car back in after the parts arrive at the dealer.

On another issue -- keyless entry failure to operate in certain locations -- I'm informed that PAG engineers are in Chicago testing a new antenna amplifier module for the 315 MHz key receiver that has the potential to completely cure any remaining issues with the Enter and Drive system. There are different places in Cincinnati where the system fails to operate correctly and the dash display says "Key Not Recognized" and sets off the alarm. Fun!

The first round fix (my car already had it installed from the factory) involved adding a filter between the antenna amplifier and the key module that rejected strong 104.9 or 105.1 MHz FM stations that produced an overload on the 315 MHz key channel via 3rd harmonic distortion. That took care of all the rural area problems with the keyless entry systems, but problems remain in big metro ares. My background if RF engineering makes me think the problem could involve 3rd-harmonic mixing in the 315 MHz key receiver being subjected to 929-932 MHz paging transmitters that are rife in large cities. I'll report what I find.

My PCM totally failed
 

Well it gets worse. My Burmester Panamera first had and still had as of last Thursday some can't find keys issues. Also in first week when the car was restarted steering wheel did not return to memoru location, that was fixed with software reload. Last Thursday no audio on morning commute.. Dealer Friday says PCM failed. Hope this fixes all of the glitches. Car is a Nov build. By the way I got a base Cayenne as a loaner.

Other than these bugs it is one of the finest cars I have ever owned.


Regards

Richard

My PCM had a fit the other day while I was using an Ipod touch. Rebooted several times. It worked okay after but the alternator was NOT the fix.

Anyone had issues with the PDK? Mine occasionally refuses to go into third gear despite manually trying to go into third, just goes between second and fourth. It usually goes away after a minute but I dint like it. The dealer did not have a clue and thought it may go away after alternator fix, it didn't.

PCM Rebooting--furhter issues anyone?
 

Took delivery of my P4S a few days ago. Last night, I started the car, backed out, SAT went quiet for a second, then came back. ALL my presets for all radio bands were gone (only the selected station displayed), Vehicle info display was gone (all the data lines I had customized were blank), and the time setting to display time on the chrono had set back to default off.

I reset all, then started the car a couple of times, all OK.

Are these the sypmtoms of the PCM reboot issue?

Well, it might share some common elements. My rebooting went away (so far) when the dealer was instructed by Atlanta to re-flash the firmware in the PCM. When mine was acting up, it would start by the audio going quiet at the same time the PCM screen went blank, just like re-starting the car.

Then, the white screen with the color Porsche logo would come on and the start-up sequence would complete. The audio would come back and my phone would re-sync. All better.

Two minutes later, the same thing would happen. And, every two or three minutes again and again until I arrived at my destination.

The dealer techs said they found a fault code having to do with the "gateway" which is a common element to all of the entertainment and navigation modules in the car. I assume it must be the MOST bus controller or something similar.

The dealer said my car took two or three times as long as Atlanta thought it should to swallow the firmware upload when they re-flashed it. The dealer has a spare controller module in stock if the re-booting comes back due to not knowing if the controller is at fault for the slow upload or if their laptop is just slower than most at doing its job.

YMMV

I never lost any information during the re-boots except for the trip odometer would seem to get behind in accumulating distance for the durations of the re-boots as I traveled down the highway. After a couple dozen re-boot cycles, the trip odo was about 15 miles behind the permanent readings without any resetting by me.

One thing that might be related to the symptoms you describe is if you switched keys between your different trips. Each Enter and Drive key is associated with a preferred setting for each of the memory variables like seat, mirror and steering wheel position, radio stations and other PCM settings. Could that be it? Check the owners manual for more info on this "feature".

I had a reflash and no issues since (fingers crossed).

UPDATE: It was the memory function tied to the key and person seat memory buttons. I have the sport seats, so PCM settings are also saved. I (or the detailer) had hit a button that had not been set yet, so it loaded default factory settings only. This cleared all my current settings, giving the impression of a reboot.


Thinking now that it might be fine and the culprit is the memory function. According to the manual, if the memory seat funtion is on, the settings, including PCM, are saved to the key at locking. If it is off, no settings are saved. I had the car detailed yesterday, had the problem right after. Perhaps he turned the memory off, locked the car then unlocked it. That could clear the settings. As the PCM was set on iPod, I didn't notice anything until a bit later. Assumed a reboot but that wouldnt explain the loss of all the other settings. Sound right?

Good to hear that you got it sorted out.

I had the PCM reboot today. Was talking on bluetooth phone (blackberry) and the PCM rebooted. Came back in about 15 seconds.

How do I find out when the car was built?

Look on the drivers door jamb....it should be there just like the 997.

Rip-off
 

Get this fixed while your vehicle is still under warranty. My Cayenne is no longer under warranty and when I called the dealer I was told that the Radio had to be replaced! They wouldn't even look at it to see if it needed a software update or need a disk/storage unit. I asked for a price - $4200 big ones. Porsche dealers have a monopoly here because you have to be a licensed dealer to have access to programming the unit. So it can't be fixed in the aftermarket. So, when your vehicle first starts doing this, get it fixed under warranty or sell it!

lol .. for $4200 I would of traded it in ..

PCM Re-booting in my Porsche Cayenne
 

My experience with rebooting PCM (on Cayenne TT), is that the antenna cables behind it were not seating properly, especially the GPS antenna.
Once I used zip ties and glued a plastic base to thread zip ties through it, to hold the end of antenna tight to the back of PCM, rebooting stopped.
I assume programming for the PCM scans for connection to signals, and if signal goes in/out frequently, PCM does a reboot to reset itself.
Since I did the zip tie thing on the Cayenne, I have not seen one reboot yet, thats about 2 years now. Before doing so, I would have reboot often, especially when using GPS.
I have a thread on this somewhere on here, in the Cayenne forum.

Ciaka what year of Cayenne do you have? I am experiencing this issue on my 2015

Mine is 2005. The gps cable connector is tiny and brittle. If Gps cable is loose it causes PCm to try reset itself. After reset pcm checks again. If not fixed. Reset here we go again.
removing radio should be easy to look behind.

Very interesting this thread resurfaced as this happened to me this AM in my 2011 Panamera Turbo - I have issues w/ entry & drive // the driver door lock/actuator - I recently had a bad tire swapped out and im thinking this may have something to do with memory as I manually locked the car last night and manually unlocked it this AM... will see how things progress but I have enough on my plate as it is and dont need to add a new PCM to the list :(

Porsches are very sensitive to voltage variations, so make sure your battery is good and charged up too, to eliminate that possibility.

apparently this is happening to many panamera/cayenne owners - has to do w/ sirius XM

Happening to me this morning in my Panamera while using XM. Very upsetting...

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 :D)...


Good luck to all!!!

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

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.

2012 panamera turbo s PCM Reset
 

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.

Mr. Z
 

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
 

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 ...