msingh5649

Looking for feedback on a weird issue on my 2009 Cab.
I have PCM 3.0 and just activiated XMRADIO. When I start in the morning and switch to XM, I see the right song that is playing-but get no audio
Switch to FMRADIO and audio is loud and clear. Switch back to XM and nothing.
Keep driving for 30+ minutes and audio starts to play, and then is perfect until I turn off the car again.

Just took it to dealer and they think it needs a new PCM unit-but there are not any available in the Porsche system, even back in Germany and besides it costs $3000
Anyone have this issue?

Any ideas?

Thanks

Bruce In Philly

2009 C2S 126K

That is odd..... I recommend you contact Becker repair in NJ. While the unit denotes BOSE, it is made by Becker in Germany and they have a repair facility in NJ.

My PCM will go silent when it overheats. If I am playing for an extended period and an elevated, but not loud, level.... it will go silent IF I shut it off... will come back on but silent... say to get gas... I need to shut the whole unit down for say 20 minutes to cool (can't even use the maps so it will cool). Really a pain on a long drive. One weekend, I will pull out the unit and test the fan in there... I think I remember hearing a fan run on hot days and playing the unit.... Anyone have information on this fan? I don;t know if it is the PCM head unit overheating or the amp under the passenger seat.

If you are experiencing what I am, then when it is silent the woofer still plays, do you hear something coming from the rear sub woofer? The sub in the back runs off of its own amp fed by a fiber optic cable ... so should the problem be with the amp, located under the passenger seat, the woofers will still play. Else the problem is upstream in the main PCM unit. Probably.... but not sure. Becker in NJ should be able to help.

Please post what you learn.

Peace
Bruce in Philly

Jus2626

I had the same exact thing happen yesterday (while I was getting gas). Really hope this doesn't become a normal event

Bruce In Philly

It is .... something is failing in there... either the fan, the temp sensor, or something else is failing driving up resistance. It won't go away... it gets worse, and then seemed to stabilize at "annoying".

Peace
Bruce in Philly

msingh5649

Interesting feedback. Thanks Bruce. So I think my situation may be the opposite of what you are seeing. In other words, my problem goes away after the radio is on for 30+ minutes so I would guess overheating is not the issue....although it could be a weak weld or something that needs to heat up??

The problem only occurs on the XMRADIO circuit. So I am driving along, XM doesn't work at first, FM/iPHONE/AUX all are working fine. Audio from the other sources is perfect, no issues.

I switch to XM and I can see the details (what song is currently playing) but not the actual audio.
Waiting 30 minutes, and switch back to XM and it works all of a sudden.
Other odd indication is that when I drive under even the smallest bridge, the signal immediately goes out and comes back the minute I clear the bridge.
My original thought was the antenna.
Dealer however says on 09- the antenna is the same as the FM radio antenna

The other oddity I noticed was during the period where XM provides a few days of 'free service' it seemed to work fine. So my thought was there was something in the encryption of the signal that in decoding somehow creates an issue for my PCM. However I would assume the 'preview' channel is unsecured, and I still have the same issue there.

I have had XM reset the account now numerous times.

Bruce thanks for the lead with Becker-they are on holiday now, but will reaching out to them and will advise.

Thanks all

NuttyProfessor

I come from the BMW world, and this seems to be their common response too. Instead of having the unit repaired, their response is "It will have to be replaced". Seems like Porsche, BMW, and others are going down the road of "disposable parts"... when it acts up, just replace the whole darn thing. Curious, don't you think an aftermarket radio system would be more practical than another problematic $3,000 Porsche radio? Does this unit support Bluetooth? If so, wouldn't Spodify, Pandora, and other streaming services make more since than XM radio?

msingh5649

I would tend to agree with the option of aftermarket, and in fact the dealer told me to go that way as well.
Outside of the aesthetic change however, I worry about the other features that connect into the PCM and how they continue to work.
As example I get details on MPG etc on the display. I am not dying for that detail but tells me there is integration with other systems.
The dealer said 'Easy peasy' we just splice wires etc....
I get a bit queasy splicing wires because it introduces risk and I have seen weird outcomes the render themselves much later that are related to bad splice, moisture, etc.

Otherwise I would go there in a heartbeat.

NuttyProfessor

I completely understand your concern. I tend to prefer the stock units in my cars. But I think they have a point. The signal that usually feeds the head units are usually auxiliary data meaning it's just another data feed. Unplugging it wouldn't cause the car to malfunction. Maybe try to find one on ebay? The only problem is that like BMW and others, you'll have to get the unit mated to your car by the dealership. Frustrating isn't it?

Bruce In Philly

A dealer can mate your used box with their plug in unit quickly... 15 mnts of work, probably charge for an hour labor. It isn't a big deal.

Peace
Bruce in Philly

rootwyrm

One of the last radio rebuilders used to be local to me and even they've gotten out of the game. Units have become too complex, impossible to repair, undecipherable circuits and ICs, not to mention the legal threats against anyone who thinks they're allowed to repair something they own.

Anyways, the problem you're describing isn't overheating. It's just not. If it was overheating, you'd have symptoms on all of them, not just XM. XM doesn't require enough difference in power for that to fail but FM to immediately work. Also it wouldn't come in later. That tells me the issue is almost certainly that the XM receiver is failing to acquire satellites. XM has a really long retry before attempting reacquisition. It starts working again because it picked up the satellites. If it's not cutting in and out after it starts working? It's probably not a hold problem. This might be solvable with a software update (since old data will have old constellation data, which means it could be looking for the completely wrong points in the sky) or it may be an antenna problem or it may be an XM-specific driver in the PCM itself is failing.

Find a shop with better diagnostic knowledge to diagnose if it's a signal acquisition problem and narrow it to antenna or PCM. It's NOT possible without the PIWIS tool or similar because you need to get fairly deep into debug registers. And it's not like IntelliLink where I can walk someone through getting into developer mode, flipping to debug, and dumping the XM registers for me to interpret. And trust me, you are REALLY going to hate yourself if you put a new head unit in, have the dealer code it, and it changes nothing at all. Especially if it turns out to be something stupid like a loose RF connector or bad antenna unit (which is way, way cheaper.) If someone shows me the PIWIS menus, I probably can fumble far enough along to get some of the data needed like SNR.

Bruce In Philly

Mr Rooty may be on to somethin' here. Maybe you should just pull the head unit out and check the connections in the back. It may be as simple as that.

Peace
Bruce in Philly

msingh5649

Great ideas. I think there was a lack of expertise at the dealer I visited. My indicator was that they told me the FM antenna and XM antenna are the same. I do not believe that to be the case, from all of the documentation I can find. Good news is that they did take the unit out and check the cables. Well they said they did. So I think I will hunt down becker radio and/or a larger volume Porsche dealer.