997.2 PCM Audio stopped
03-26-2019, 09:11 AM
#16
RL Community Team
Rennlist Member
Rennlist Member
My 09 Cayenne TTS with PCM3 just recently started doing a reboot every 3-5 minutes and would not connect to my phone. The rebooting would only happen if BT functionality on the PCM was turned on - didn't matter if a phone was paired to it or connected to it. If it was enabled in the PCM - reboots every 3-5 minutes like clockwork. If by in the PCM was disabled, it would never reboot and work just fine.
Doing some online research I found some info that this has happened before with cars that have satellite radio and when the satellite companies do updates to their systems it freaks out the PCM. The fix discussed was a system update to the PCM. Took it into my dealer, had the PCM software updated and reloaded, and have driven the car about 5 hours with multiple starts and it works perfectly again. It's a shame they replaced your prior PCM as I bet an update would have cured it and you would have still had all your source functionality. Your dealer doesn't sound great either - maybe find a different one to get the current PCM that's installed straightened out.
Doing some online research I found some info that this has happened before with cars that have satellite radio and when the satellite companies do updates to their systems it freaks out the PCM. The fix discussed was a system update to the PCM. Took it into my dealer, had the PCM software updated and reloaded, and have driven the car about 5 hours with multiple starts and it works perfectly again. It's a shame they replaced your prior PCM as I bet an update would have cured it and you would have still had all your source functionality. Your dealer doesn't sound great either - maybe find a different one to get the current PCM that's installed straightened out.
03-26-2019, 10:05 AM
#17
RL Community Team
Rennlist Member
Rennlist Member
I think these are all different symptoms of different failures. The thermal shutdown is just one.... rebooting is another.... there are more.
Regarding the thermal shutdown.... I never tried pulling the fuse... I will give that a try next time however I must prepare for it, otherwise the time it takes to find and then pull the fuse just may be long enough for the thing to have cooled down.
Hoestly, I think I am just going to live with it. Sending $500 or so to Becker is not that worth it to me..... maybe a used one will do it, plenty on ebay.
Peace
Bruce in Philly
Regarding the thermal shutdown.... I never tried pulling the fuse... I will give that a try next time however I must prepare for it, otherwise the time it takes to find and then pull the fuse just may be long enough for the thing to have cooled down.
Hoestly, I think I am just going to live with it. Sending $500 or so to Becker is not that worth it to me..... maybe a used one will do it, plenty on ebay.
Peace
Bruce in Philly
03-26-2019, 05:33 PM
#18
My 09 Cayenne TTS with PCM3 just recently started doing a reboot every 3-5 minutes and would not connect to my phone. The rebooting would only happen if BT functionality on the PCM was turned on - didn't matter if a phone was paired to it or connected to it. If it was enabled in the PCM - reboots every 3-5 minutes like clockwork. If by in the PCM was disabled, it would never reboot and work just fine.
Doing some online research I found some info that this has happened before with cars that have satellite radio and when the satellite companies do updates to their systems it freaks out the PCM. The fix discussed was a system update to the PCM. Took it into my dealer, had the PCM software updated and reloaded, and have driven the car about 5 hours with multiple starts and it works perfectly again. It's a shame they replaced your prior PCM as I bet an update would have cured it and you would have still had all your source functionality. Your dealer doesn't sound great either - maybe find a different one to get the current PCM that's installed straightened out.
Doing some online research I found some info that this has happened before with cars that have satellite radio and when the satellite companies do updates to their systems it freaks out the PCM. The fix discussed was a system update to the PCM. Took it into my dealer, had the PCM software updated and reloaded, and have driven the car about 5 hours with multiple starts and it works perfectly again. It's a shame they replaced your prior PCM as I bet an update would have cured it and you would have still had all your source functionality. Your dealer doesn't sound great either - maybe find a different one to get the current PCM that's installed straightened out.
Nevertheless, I’m in a bind now since the dealer has to source a refurbished PCM and try to fix everything ...what a mess while it seemed an easy fix at least to me.
Always appreciate your great feedback and help here on the forums, many thanks again.
03-26-2019, 05:52 PM
#19
RL Community Team
Rennlist Member
Rennlist Member
Thank you sir. I do have the satellite radio option on my PCM but it was not subscribed when the rebooting issues occurred- does this still apply to the above where you mention satellite radio upgrades freak the PCM out?
Nevertheless, I’m in a bind now since the dealer has to source a refurbished PCM and try to fix everything ...what a mess while it seemed an easy fix at least to me.
Always appreciate your great feedback and help here on the forums, many thanks again.
Nevertheless, I’m in a bind now since the dealer has to source a refurbished PCM and try to fix everything ...what a mess while it seemed an easy fix at least to me.
Always appreciate your great feedback and help here on the forums, many thanks again.
What did they do with your old unit? Maybe reinstall it then update the software and see if everything comes back and works properly.
03-26-2019, 06:01 PM
#20
I never thought about what you shared PCM update etc as a solution and figure the dealer would know by default, as I had read when the PCM reboots like this it’s dying or the hard drive is going to go soon on another thread.
09-22-2019, 12:49 PM
#21
I have a 2009 997.2. I turned on the radio this morning and the radio reception is dreadful - it sounds like the stations are off their settings and the sound is crackly. If I use a USB input or a CD, the sound is normal. Can anyone offer any advice on possible fixes?
09-22-2019, 03:46 PM
#22
RL Community Team
Rennlist Member
Rennlist Member
2009 C2S 142k miles
Ensure the antennae is plugged in. Pull the shroud left off the battery ... passenger side... and look around the cabin air filter fo a dangling wire.
Peace
Bruce in Philly
Ensure the antennae is plugged in. Pull the shroud left off the battery ... passenger side... and look around the cabin air filter fo a dangling wire.
Peace
Bruce in Philly
05-30-2020, 12:47 AM
#23
Three Wheelin'
Most likely true, however I doubt the sub is taking the "RAW" signal. The PCM system is a 5.1 format that actually plays 5.1 DVDA discs. I suspect, but don't really know, that the amp/processor under the seat is translating the incoming signal and sending the .1 to the sub... it all depends where the real processing is done. Regular stereo, such as from radio has to be processed to send appropriate signals to all the speakers including the .1 sub. Again, I suspect the amp/processor is doing a bunch of work and the sub's electronics are just a simple, cheap digital to analog converter and not a decoder chip to decode the .1 sub information or create a sub signal for the bass as is needed from a stereo FM signal. But I really don't know. It would be a cheaper system to do all the work, one time at the amp/processor since the premium 5.1 system is an option. But true, all my conjecture. If I had to bet, I would bet the amp/processor's output transistors are overheating and the system is shutting down there. But who knows?
The only thing I am confident about is that the problem is thermal-related shut down and this is based on my ... oh two years? ... of experience with this problem. Of course, the question is why is it over heating, assuming I am correct? Does the amp have a little fan in there that failed.... this would be a cheap easy fix, or are the electronics just wearing out?
Update: the part number is 99764544101 ... I examined, the best I could... the pics of used units for sale around the 'net and it doesn't look like there are fan vents... heat sink fins for sure, but no fan vents. Oh well, I guess replacement is the only option... looks like $300 to $350 used. I look into this every so often and come to the same conclusion: wait till it stops working.
Update2: I just sent Becker in NJ an email asking for help... I will post back what they say.
Peace
Bruce in Philly
The only thing I am confident about is that the problem is thermal-related shut down and this is based on my ... oh two years? ... of experience with this problem. Of course, the question is why is it over heating, assuming I am correct? Does the amp have a little fan in there that failed.... this would be a cheap easy fix, or are the electronics just wearing out?
Update: the part number is 99764544101 ... I examined, the best I could... the pics of used units for sale around the 'net and it doesn't look like there are fan vents... heat sink fins for sure, but no fan vents. Oh well, I guess replacement is the only option... looks like $300 to $350 used. I look into this every so often and come to the same conclusion: wait till it stops working.
Update2: I just sent Becker in NJ an email asking for help... I will post back what they say.
Peace
Bruce in Philly
The following users liked this post:
I am the Walrus (06-18-2020)
05-30-2020, 01:38 AM
#24
RL Community Team
Rennlist Member
Rennlist Member
I am hoping it won't work... then you found the problem for all of us.
I suspect you know how to test it given you pulled the unit out.
From your picture, I read that part number as: EFB0412VHD. I found only one supplier on Amazon for $20... note the last two letters is HD and it is made in Thailand... the others without the HD are made in China... I suspect that the HD is for Heavy Duty.... but who knows. eBay has them too for about half price but from Hong Kong and a much later deliver date. Of course, plenty of substitute parts for this same little fan for way cheaper.
Peace
Bruce in Philly
Last edited by Bruce In Philly; 05-30-2020 at 03:25 AM.
05-30-2020, 11:47 AM
#25
Three Wheelin'
Wow!. Fabulous.... Good Job! Does the fan work? Just put any battery on it.... AA or a 9 volt... any little battery will make it spin... use paper clips as wires if needed. It is DC so I suspect just the red and blue wires will do it... maybe.
I am hoping it won't work... then you found the problem for all of us.
I suspect you know how to test it given you pulled the unit out.
From your picture, I read that part number as: EFB0412VHD. I found only one supplier on Amazon for $20... note the last two letters is HD and it is made in Thailand... the others without the HD are made in China... I suspect that the HD is for Heavy Duty.... but who knows. eBay has them too for about half price but from Hong Kong and a much later deliver date. Of course, plenty of substitute parts for this same little fan for way cheaper.
Peace
Bruce in Philly
I am hoping it won't work... then you found the problem for all of us.
I suspect you know how to test it given you pulled the unit out.
From your picture, I read that part number as: EFB0412VHD. I found only one supplier on Amazon for $20... note the last two letters is HD and it is made in Thailand... the others without the HD are made in China... I suspect that the HD is for Heavy Duty.... but who knows. eBay has them too for about half price but from Hong Kong and a much later deliver date. Of course, plenty of substitute parts for this same little fan for way cheaper.
Peace
Bruce in Philly
On a side note Porsche didn’t completely cheap out on making this circuit board. They did conformal coat the board so if it gets wet it can help prevent damage to the circuitry.
Update: The fan does not automatically turn on with the radio. Probably turns on when it gets warm, but I will need to have it shut down to test that theory. It is easy to just put you finger into the blades to see if it is running. Don’t worry it will stop before it hurts you.
Last edited by doclouie; 05-30-2020 at 12:17 PM.
05-31-2020, 05:15 AM
#27
Racer
Just a tip on the fan, it's actually EFB0412VHD-F00 - the F00 means it has the tach output (blue wire). These are in stock at Digikey and other electronics suppliers. It's a bog standard 40x20mm 12vdc computer fan with tach out. Though Delta are usually reliable, quality units, if noisy. I suspect the tach output is used to trigger a shutdown if the microprocessor wants the fan running, but it appears to be stalled.
I've poked around the Bose amps in the 997.2 with PCM3 system. The amp does a TON of signal processing. It's got a pretty respectable DSP with licensed audio decoders for DVD-A and other formats. It has multiple channels of power amps, 10 channels actually. Curiously, low level signal to the subwoofer and turn-on signal. The sub has its own power amp.
The optical signal can carry a lot of data in multiple formats. The software in the unit understands a lot of different audio formats and I'm sure some Bose/Porsche specific protocols for things like enabling speed-sensitive audio, surround simulation, sending the nav voice guidance to the center speaker and other stuff.
All the aftermarket MOST converters I've seen use the generic MOST chips and only do two-channel stereo. The multi-channel features require licensed software (or a metric ton of work implementing the software) and of course, any Dolby or DVD licenses. Figuring any of it out is nearly impossible without a ton of lab equipment and databooks that are only provided to OEM partners by the silicon vendors.
Here's the guts of one kind of blocked out.
https://rennlist.com/forums/997-foru...al-blocks.html
If you're adventurous and think it might be a heat issue, you might try putting new thermal paste on all the heat sinked components. Open it up and you'll see the typical white-goo, all dried up. Carefully clean it up with alcohol and use a quality computer thermal paste. Nice thin, even coat so that all the metal on the amp chip is coupled up to the metal heatsink, without making a bunch of squeeze out. It isn't rocket science.
I've poked around the Bose amps in the 997.2 with PCM3 system. The amp does a TON of signal processing. It's got a pretty respectable DSP with licensed audio decoders for DVD-A and other formats. It has multiple channels of power amps, 10 channels actually. Curiously, low level signal to the subwoofer and turn-on signal. The sub has its own power amp.
The optical signal can carry a lot of data in multiple formats. The software in the unit understands a lot of different audio formats and I'm sure some Bose/Porsche specific protocols for things like enabling speed-sensitive audio, surround simulation, sending the nav voice guidance to the center speaker and other stuff.
All the aftermarket MOST converters I've seen use the generic MOST chips and only do two-channel stereo. The multi-channel features require licensed software (or a metric ton of work implementing the software) and of course, any Dolby or DVD licenses. Figuring any of it out is nearly impossible without a ton of lab equipment and databooks that are only provided to OEM partners by the silicon vendors.
Here's the guts of one kind of blocked out.
https://rennlist.com/forums/997-foru...al-blocks.html
If you're adventurous and think it might be a heat issue, you might try putting new thermal paste on all the heat sinked components. Open it up and you'll see the typical white-goo, all dried up. Carefully clean it up with alcohol and use a quality computer thermal paste. Nice thin, even coat so that all the metal on the amp chip is coupled up to the metal heatsink, without making a bunch of squeeze out. It isn't rocket science.
05-31-2020, 11:25 AM
#28
RL Community Team
Rennlist Member
Rennlist Member
Larry, thanx for the detail !!! I hope one of you guys can crack this cut out issue. I, after having a few too many Pilsner Urquells, went ahead and ordered that fan. It is cheap so what the heck. If neither of you crack this problem, I will swap out the fan just to see what happens. Hey, I am an optimist... and am looking for more Covid projects. Othwise I'll be polishing the paint off of my car. I may try the thermal paste repair too.
I really think the cut out is due to thermal shutdown. It has been happening to me for years now and is definitely more prevalent in warmer weather, and when I run the system at higher volume..... but I have been wrong before.... just ask my wife. I never realized how wrong I was until I got married.
Regarding noise cancellation.... new on on me. As you point out, it may be poorly implemented. My ear/brain system is very sensitive to those out-of-phase signals... they drive me nuts... so I think I would have been aware of it by now. Or, maybe it is switched off when you select Linear as I have it configured. I find that it also screws with stereo imaging. This Bose 5.1 system actually does image (well as good as you may get in a car) if you play that DVD A of Queen Night at the Opera.... pretty cool.
Peace
Bruce in Philly
I really think the cut out is due to thermal shutdown. It has been happening to me for years now and is definitely more prevalent in warmer weather, and when I run the system at higher volume..... but I have been wrong before.... just ask my wife. I never realized how wrong I was until I got married.
Regarding noise cancellation.... new on on me. As you point out, it may be poorly implemented. My ear/brain system is very sensitive to those out-of-phase signals... they drive me nuts... so I think I would have been aware of it by now. Or, maybe it is switched off when you select Linear as I have it configured. I find that it also screws with stereo imaging. This Bose 5.1 system actually does image (well as good as you may get in a car) if you play that DVD A of Queen Night at the Opera.... pretty cool.
Peace
Bruce in Philly
05-31-2020, 11:58 AM
#29
Three Wheelin'
Thanks for the in depth reply Larry. I work in the electronics industry as an engineer so I love those type of details. Not sure why they chose a silver immersion finish as it oxidizes pretty bad through time. I have thermal compound so I will crack it open today and clean it up and replace the paste to see if that helps. My radio does not cut out very often, but hopefully this will take care of the issue. I originally was going to open the case and conformal coat the board, but it was already done.
The following users liked this post:
doclouie (05-31-2020)