PCM Issue with recent iOS Update?
06-13-2020, 06:03 PM
#242
Pro
My car's XM reboot problem began May 20. The dealer performed the handover reset on May 21, and all was well for the next 6 days, although I did not use the car every day. Then the problem returned.
I did the second handover reset myself on May 29. The PCM has been through about 7 total hours of service and 6 or more vehicle on/off cycles since then, and everything is still working correctly. I don't want to jinx it, but I think my PCM is back to normal now.
I did the second handover reset myself on May 29. The PCM has been through about 7 total hours of service and 6 or more vehicle on/off cycles since then, and everything is still working correctly. I don't want to jinx it, but I think my PCM is back to normal now.
06-13-2020, 07:55 PM
#243
Rennlist Member
Sigh. I was just thinking it was probably safe to plug the antenna back in. 
At this point I'm going to wait a full week after the last "It's back" message is posted to any of the forums for vehicles with PCM 3.1.
At this point I'm going to wait a full week after the last "It's back" message is posted to any of the forums for vehicles with PCM 3.1.
06-27-2020, 12:02 AM
#244
1st Gear
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Need some help
Hello, I was having the same issue with reboot pcm.. let it wait and it look is fixed but for some reason now I can not used my Iphone to play audio BT AUX ! Only phone calls. Any ideas?
06-27-2020, 12:50 AM
#245
06-28-2020, 04:16 PM
#246
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PCM-PSM issue
Guys
Has anyone experienced an error message that PSM deactivated? The message went away when I reset the PCM system but I am planning a track session and want to know if this is a separate issue or related to the PCM. Have others have experienced the same message? Did a second PCM reset resolve the problem. I have a 2013 991.1
Has anyone experienced an error message that PSM deactivated? The message went away when I reset the PCM system but I am planning a track session and want to know if this is a separate issue or related to the PCM. Have others have experienced the same message? Did a second PCM reset resolve the problem. I have a 2013 991.1
06-28-2020, 04:29 PM
#247
Originally Posted by Zippy991
Guys
Has anyone experienced an error message that PSM deactivated? The message went away when I reset the PCM system but I am planning a track session and want to know if this is a separate issue or related to the PCM. Have others have experienced the same message? Did a second PCM reset resolve the problem. I have a 2013 991.1
Has anyone experienced an error message that PSM deactivated? The message went away when I reset the PCM system but I am planning a track session and want to know if this is a separate issue or related to the PCM. Have others have experienced the same message? Did a second PCM reset resolve the problem. I have a 2013 991.1
I wouldn't worry about it until it pops up again. It could also be due to a misfire. Minor misfires cause the PSM to be disabled and then multiple/major misfires put the engine into limp mode (PSM error, plus "Engine Fault"). Misfires are usually due to bad ignition coil(s).
Last edited by Class5Kayaker; 06-29-2020 at 01:25 PM.
06-28-2020, 04:50 PM
#248
Rennlist Member
Most common cause of "PSM deactivated" is one or more bad ignition coils. The ECU reacts to that condition by throwing seemingly-random messages. If that's the problem, it'll probably become obvious on the track.
06-30-2020, 07:34 PM
#249
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PCM-PSM issue
I cannot feel a misfire in the exhaust, and no error codes on my generic code reader. Nonetheless, I will watch for the misfire, likely it is intermittent. Perhaps its time to do plugs and coils even though only 30,000 miles, but 7 years.
Thanks Noah and Class5 for the responses..
07-17-2020, 04:46 AM
#250
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My PCM started rebooting again this past week, and with a vengeance in that it’s rebooting every 5 mins instead of the usual 10. Performing vehicle handover and reset does not fix the problem. And this is after I tried updating the PCM software, but it was already at v3.43 and there is no further update.
Rather than removing the SiriusXM module from the PCM, which requires removal of the unit, I have just unplugged the wire connection for the SDARS SiriusXM antenna by following the instructions here: https://rennlist.com/forums/991/1125...-2019-gts.html
I won’t miss having SiriusXM through the PCM, as I installed the Joyeauto CarPlay unit and could stream SiriusXM that way. Will see whether this will finally fix the reboot issue!
Rather than removing the SiriusXM module from the PCM, which requires removal of the unit, I have just unplugged the wire connection for the SDARS SiriusXM antenna by following the instructions here: https://rennlist.com/forums/991/1125...-2019-gts.html
I won’t miss having SiriusXM through the PCM, as I installed the Joyeauto CarPlay unit and could stream SiriusXM that way. Will see whether this will finally fix the reboot issue!
07-17-2020, 03:23 PM
#251
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My PCM started rebooting again this past week, and with a vengeance in that it’s rebooting every 5 mins instead of the usual 10. Performing vehicle handover and reset does not fix the problem. And this is after I tried updating the PCM software, but it was already at v3.43 and there is no further update.
Rather than removing the SiriusXM module from the PCM, which requires removal of the unit, I have just unplugged the wire connection for the SDARS SiriusXM antenna by following the instructions here: https://rennlist.com/forums/991/1125...-2019-gts.html
I won’t miss having SiriusXM through the PCM, as I installed the Joyeauto CarPlay unit and could stream SiriusXM that way. Will see whether this will finally fix the reboot issue!
Rather than removing the SiriusXM module from the PCM, which requires removal of the unit, I have just unplugged the wire connection for the SDARS SiriusXM antenna by following the instructions here: https://rennlist.com/forums/991/1125...-2019-gts.html
I won’t miss having SiriusXM through the PCM, as I installed the Joyeauto CarPlay unit and could stream SiriusXM that way. Will see whether this will finally fix the reboot issue!
07-18-2020, 10:15 AM
#252
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Unfortunately, it didn't. The SiriusXM antenna was disconnected, as the PCM shows a message to "Check XM Antenna", yet the reboot persisted - at now 5 or 10 min. intervals. Looks like the hard drive has bad sectors and needs to be replaced.
12-21-2021, 12:51 PM
#253
Thank you!
you guys are a Godsend!
I luv this Porsche community
for me it happened right after I bought a new iPhone 13 Pro two days ago
Navi working fine
but then Bluetooth and iPhone pairing not working
then few hours driving to a wedding that afternoon PCM starts cycling turning off than turning back on to Carrera S load screen
doesnt work whether you push accept button on traffic disclaimer or not
Navi and Maps stuck at loading
I have car hooked up to CTEK trickle battery charger. But you can tell that PCM constantly recycling every 5 minutes with a little click or whirr
Just pulled my PCM fuse and finally quiet now
i previously had tried reset at dealer yesterday
will probably try again later
if doesn’t work going to try to have JLSO help with hard drive
This should be a Class Action lawsuit
i care Navi system should not go dead and require $4000 replacement after Bluetoothing an iPhone because of hard drive memory issues or file corruption
I luv this Porsche community
for me it happened right after I bought a new iPhone 13 Pro two days ago
Navi working fine
but then Bluetooth and iPhone pairing not working
then few hours driving to a wedding that afternoon PCM starts cycling turning off than turning back on to Carrera S load screen
doesnt work whether you push accept button on traffic disclaimer or not
Navi and Maps stuck at loading
I have car hooked up to CTEK trickle battery charger. But you can tell that PCM constantly recycling every 5 minutes with a little click or whirr
Just pulled my PCM fuse and finally quiet now
i previously had tried reset at dealer yesterday
will probably try again later
if doesn’t work going to try to have JLSO help with hard drive
This should be a Class Action lawsuit
i care Navi system should not go dead and require $4000 replacement after Bluetoothing an iPhone because of hard drive memory issues or file corruption
I posted it in my initial post (post #20):
Row B, Fuse #10, 25 amp in the driver's footwell
Waiting to hear back from my SA (I got his voicemail so I emailed him). He's great and knows I wrench on my car a lot so I'm sure he'll email me the actual instructions from Porsche.
12-21-2021, 05:57 PM
#254
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I received an email today from PCNA addressing this issue. Looks to be the same resolution as has already been discussed in this thread.
Dear Mr. Evans,
We are aware that some of our customers are experiencing an issue with their vehicle’s central communication unit, known as the Porsche Communication Management (PCM), causing it to continuously reboot.
If your vehicle is equipped with PCM and you are experiencing this condition, performing a hard reset of the PCM should resolve the concern. To perform this reset please follow these steps:
***Before performing this procedure, ensure that your vehicle is located outdoors. Please note that hard resetting the PCM will remove all personalized settings
If after performing this procedure your vehicle continues to experience consistent reboots please contact your local authorized dealership to schedule an appointment for further diagnosis.
Dear Mr. Evans,
We are aware that some of our customers are experiencing an issue with their vehicle’s central communication unit, known as the Porsche Communication Management (PCM), causing it to continuously reboot.
If your vehicle is equipped with PCM and you are experiencing this condition, performing a hard reset of the PCM should resolve the concern. To perform this reset please follow these steps:
***Before performing this procedure, ensure that your vehicle is located outdoors. Please note that hard resetting the PCM will remove all personalized settings
- Press and hold the INFO button for approximately 10 seconds until the PCM reboots.
- Press the CAR button.
- Press the OPTION button or touch the tab of the same name in the header.
- Select "SET PCM system">>"Reset PCM".
- Select "Vehicle handover" This resets all settings to predefined values and deletes your personal settings and data (including addresses, destinations, radio stations, phone numbers, as well as the recordings in the Sport display).
- Confirm the relevant prompt by selecting "Yes".
If after performing this procedure your vehicle continues to experience consistent reboots please contact your local authorized dealership to schedule an appointment for further diagnosis.
You do lose presets but obviously that's the least of the issues.