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".