PCM Restarting XM radio fault?
02-14-2021, 01:00 AM
#137
02-14-2021, 10:41 AM
#138
Man, maybe I got lucky, but I solved this issue in two steps:
1. Called XM, gave them my transponder ID, and told them to remove the transponder from any updates - present or future.
2. Reset the PCM per instructions posted here.
It's been rock solid ever since.
1. Called XM, gave them my transponder ID, and told them to remove the transponder from any updates - present or future.
2. Reset the PCM per instructions posted here.
It's been rock solid ever since.
02-21-2021, 08:56 AM
#139
Racer
Your Hard drive is failing but ok in the primary area used. The update gets downloaded to another section of disk which is defective. Then when the update tries to write over the primary area it can't because the file is corrupted because it was loaded to a defective disk area. The real answer is to replace the HD. It's a fairly straight forward process. You can replace it with a SSD and remove any moving parts from the future. Most Panny's use a SATA hard drive so replacement is easy. Some, like mine use a IDE hard drive and that is a little more challenging. I had to use a IDE to mSATA adapter with a mSATA hard drive. Clonzilla will copy your old data to your new and then you simply swap the drives. If your Hard drive is completely toast, there is a post here on how to partition a new drive, then installing the update disk will copy the files you need. Both the update disk and the partition information are available in other threads
02-21-2021, 06:54 PM
#140
Eh, I tend to disagree. The chances of tens of thousands of Porsche owners (according to Porsche and XM) having the same HD failure in the exact same sectors of a disc that XM uses to update itself is almost beyond plausibility. Also, those sectors would all have to have been functional for all of the XM updates since 2012, but suddenly failed all at the same time in 2020. That would be really....really....statistically odd. IMHO, the issue is an XM service update borked something within the software package that caused the PCM to get confused. When a computer gets confused, it freaks out and reboots itself. I am not saying that your hard drive was not bad - it sounds like swapping it out fixed the issue for you. But that is not the case with everyone.
Anyway, I am glad you (and others) got this sorted out. I'm not brave enough to try and test my theory by starting XM back up... but I might try it just out of morbid curiosity.
Cloned the IDE HDD to another Toshiba IDE HDD. PCM came back to life, but would still reboot. Double checked the HDD and the partitions, and everything is per spec. Still rebooting. Called and canceled XM, but it was still rebooting. Just checked it today, and XM is canceled and not sending broadcasts to my PCM, and the radio hasn't rebooted! My PCM is still on v1.35, and looking to update it. I still have the maps, and my iPod works, so I'm happy. I don't use XM anyway, so no loss.
Last edited by Shrike071; 02-22-2021 at 09:49 AM. Reason: fixed quote attribution
02-22-2021, 08:55 AM
#141
Racer
10,'s of thousands? Most Porsche owners, me included, were successful with a simple reset. Yes this software required a reset for most. However for the remaining ones with problems, which are maybe down to a few hundred, they likely have hard drive issues. My cloning worked because my HD had not failed, I replaced it pre-emptively. Yours didn't work because you cloned bad sectors of the hard drive. You would have to go to the fresh format, then partition and run the update. Given everything is working, and you don't use XM, there isn't much of a need. Version 1.35 means you are on the earliest variant of the PCM3.1.
02-22-2021, 09:46 AM
#142
10,'s of thousands? Most Porsche owners, me included, were successful with a simple reset. Yes this software required a reset for most. However for the remaining ones with problems, which are maybe down to a few hundred, they likely have hard drive issues. My cloning worked because my HD had not failed, I replaced it pre-emptively. Yours didn't work because you cloned bad sectors of the hard drive. .
You said
The real answer is to replace the HD.
Blindly replacing the hard drive due to a bootloop makes as much sense as changing the engine out because a coil died. Sure, it'll do the trick, but you skipped a lot of diagnosis to get there.
Last edited by Shrike071; 02-22-2021 at 10:03 AM.
02-22-2021, 10:39 AM
#143
Racer
Dude, you quite clearly took issue with my statement of "maybe I got lucky..." because you came back and told me "your hard drive is failing...". It is not and that's what I said. Yes, 10's of thousands of Porsche owners had the issue with the XM push. The vast majority of them were able to clear it with a simple reset. I did not clone anything - I did not replace my drive. That quote was from another post where the hdd did not work - NOT my post.. A software update (usually) does not choose a specific part of the hard drive platter to write to. It uses random, available space. Software also does not write itself as one large "block" of data. That data is spread out over the available space on the drive. (Its also why some hard drives need to be de-fragmented...). Programmers usually don't specify what is written to what portion of the platters because there are simply too many variables - and its a waste of time.
You said
That is not the real answer. The CORRECT answer is to call XM and have them remove the transponder from their database, reset the unit, and THEN see if you still have issues. If you do, THEN start looking at your hard drive. XM pushed a bad package that created a conflict with Porsche's internal code. When the PCM ran into the bad code, it rebooted as a (common) self-preservation measure. My guess is the code has since been revised and is most likely just fine. I don't care enough to go through the hassle of testing.
Blindly replacing the hard drive due to a bootloop makes as much sense as changing the engine out because a coil died. Sure, it'll do the trick, but you skipped a lot of diagnosis to get there.
You said
That is not the real answer. The CORRECT answer is to call XM and have them remove the transponder from their database, reset the unit, and THEN see if you still have issues. If you do, THEN start looking at your hard drive. XM pushed a bad package that created a conflict with Porsche's internal code. When the PCM ran into the bad code, it rebooted as a (common) self-preservation measure. My guess is the code has since been revised and is most likely just fine. I don't care enough to go through the hassle of testing.
Blindly replacing the hard drive due to a bootloop makes as much sense as changing the engine out because a coil died. Sure, it'll do the trick, but you skipped a lot of diagnosis to get there.
02-22-2021, 12:38 PM
#144
Did I say otherwise? No. But you are actually posting in a thread specific to the reboot problem that started in May-ish of 2020. An XM-specific problem - confirmed by Porsche. If the problem started in early 2020, the XM update is the most likely cause of the problem. Not a bad drive.
Quoting from the bulletin listed here:
Sirius XM Radio recently sent out refresh signal and it has caused major functional issues with the PCM (Center Touchscreen) affecting virtually all Porsche vehicles.
Last edited by Shrike071; 02-22-2021 at 12:56 PM.
02-22-2021, 02:27 PM
#145
02-22-2021, 02:54 PM
#146
That said, with some of the other options out there for media and streaming, I am not sure there is an argument to be made in favor of using XM radio at all anymore.
02-25-2021, 09:16 AM
#149
Advanced
Thread Starter
No way to tell for sure, but the reset did fix the issue. When I did the reset I waited a couple of weeks before re-initializing my XM feed. Hope you can resolve it.