PCM microphone gain/location?
Discussion
I have a 2014 981 Boxster S and I'm having some trouble with the quality of the audio of my phone when used through PCM.
The main problem is that the person on the other end says I sound very distant and quiet. It's as if the audio is being recorded on my phone which usually stays in my handbag on the passenger seat or behind one of the seats if I have a passenger. The problem is the same whether I use my work phone (iPhone) or my personal phone (Sony Android). I've even put the SIM in the SIM tray in the PCM itself to eliminate the bluetooth connection - the problem is the same.
In the phone settings, there's an option to adjust microphone sensitivity. It apparently does little or nothing.
My car also has voice control, and I have to shout to get it to understand me.
Lots of googling leads me to believe that the microphone might be inside the steering column. Can anyone confirm its location? Perhaps the mic has come loose and slipped out of the correct position? Is there some sort of PCM service mode I can access that will allow me to adjust the base microphone gain or test it some way?
Second curiosity question: When connected to my Android phone, I can see all my emails and texts. When connected to my iPhone I can only see texts that arrive after the connection was made. Emails don't seem to come through at all.
I couldn't find very much information on this - the owner's manual doesn't even mention where the PCM microphone is located.
Many thanks for any ideas!
The main problem is that the person on the other end says I sound very distant and quiet. It's as if the audio is being recorded on my phone which usually stays in my handbag on the passenger seat or behind one of the seats if I have a passenger. The problem is the same whether I use my work phone (iPhone) or my personal phone (Sony Android). I've even put the SIM in the SIM tray in the PCM itself to eliminate the bluetooth connection - the problem is the same.
In the phone settings, there's an option to adjust microphone sensitivity. It apparently does little or nothing.
My car also has voice control, and I have to shout to get it to understand me.
Lots of googling leads me to believe that the microphone might be inside the steering column. Can anyone confirm its location? Perhaps the mic has come loose and slipped out of the correct position? Is there some sort of PCM service mode I can access that will allow me to adjust the base microphone gain or test it some way?
Second curiosity question: When connected to my Android phone, I can see all my emails and texts. When connected to my iPhone I can only see texts that arrive after the connection was made. Emails don't seem to come through at all.
I couldn't find very much information on this - the owner's manual doesn't even mention where the PCM microphone is located.
Many thanks for any ideas!
I'm really keen on trying to find a solution for the microphone problem, because although it's a small issue, it does detract from what could otherwise be described as the perfect car. Because I work with teams based in California, I often need to join conference calls in the evening when I'd rather be getting home. This issue means I can't take the Porsche if I think I may need to join a call, even if it's a beautiful day - and have to fall back on my ancient BMW with its stone age wired-in Nokia bluetooth setup.
I could perhaps ask a local dealer to help, which could be Brooklands service centre, Porsche Guildford, or Porsche Reading. But assuming that the microphone is not something the diagnostics systems can check, it would need manual fiddling and that could get very expensive very quickly. If there is an adjustable gain setting somewhere within PCM, then it probably does need a diagnostic CD/DVD or some sort of plug in module to access. Does anyone know anyone who has access to these things out of the context of a dealership service centre?
Thanks!
I could perhaps ask a local dealer to help, which could be Brooklands service centre, Porsche Guildford, or Porsche Reading. But assuming that the microphone is not something the diagnostics systems can check, it would need manual fiddling and that could get very expensive very quickly. If there is an adjustable gain setting somewhere within PCM, then it probably does need a diagnostic CD/DVD or some sort of plug in module to access. Does anyone know anyone who has access to these things out of the context of a dealership service centre?
Thanks!
Thank you James,
I believe the car had PCM fitted from the factory as it's on the build sheet. It didn't have voice control or cruise control fitted however, and I have Brooklands service centre retrofit those a few months ago and they are both options on the Tequipment page. Cruise control works perfectly, and I drive quite a bit on the M4 average speed camera zones so it's an essential. I would have liked ACC had it been available, but since my car is a manual I'm not sure how much use it would have been. Voice control is not essential, but I found it worked very well on a 718 loaner I had for a couple of months and I found I missed it when I didn't have it!
I believe the car had PCM fitted from the factory as it's on the build sheet. It didn't have voice control or cruise control fitted however, and I have Brooklands service centre retrofit those a few months ago and they are both options on the Tequipment page. Cruise control works perfectly, and I drive quite a bit on the M4 average speed camera zones so it's an essential. I would have liked ACC had it been available, but since my car is a manual I'm not sure how much use it would have been. Voice control is not essential, but I found it worked very well on a 718 loaner I had for a couple of months and I found I missed it when I didn't have it!
short-shift said:
Is that just a software update/fit, or did it also include some physical work involving the microphones or their wiring into the Quadlock connector?
I don't know about adding microphones, but it definitely is a hardware upgrade. The standard indicator stalk doesn't have the button to activate voice control, so the stalk was definitely replaced. Cruise control also adds a stalk in place of the blanking plate, and that must plug in somewhere too. Whether it just fits into an existing socket on the column, or whether wiring needs to be installed I don't know. Either way, both additions involve getting inside the steering column enclosure, which is why I mentioned them. I'm going to call up Brooklands and see what they say.Ok so I got the trim off and sure enough there are two microphones connected via a blue and a purple connection block. I haven't figured out how to uncouple the connectors yet but it could be a poor connection. If that doesn't help I'll see if I can find out how to get to the back of the PCM. Will the connectors be located behind the screen?
OK I found a video showing the addition of Apple Carplay to PCM 3.1. While I don't want to do that, it does show how to remove the PCM unit from a 991 so I'm sure it'll be the same or similar in a 981.
If you do watch the video, beware. The guy has a really long thumbnail for no apparent reason and it's plain weird!
https://www.youtube.com/watch?v=_rKfUlZMcvc
If you do watch the video, beware. The guy has a really long thumbnail for no apparent reason and it's plain weird!
https://www.youtube.com/watch?v=_rKfUlZMcvc
About a week ago I popped into OPC Guildford on the admittedly very slim offchance of bagging myself an allocation for the new 718 GT4. While I was there I queried the techs about my problem. They said they'd heard of the issue but I'd have to book the car in, so that's what I did. Worryingly, the tech was convinced that the microphones are located above the rear-view mirror.
As the diagnostic isn't going to be free, I got myself a new multimeter as my old one has gone AWOL. I pulled out the PCM head unit as you suggested and checked for continuity on all four wires, and it's there. I also checked the resistance of both mics - one is 5kOhms and the other is 6kOhms. I then opened up one microphone to find a tiny PCB with a very small IC, some tiny surface mount components and a cylindrical-shaped component with felt on one end which I am certain is the actual mic. So they aren't just simple condenser mic on wires, there's a lot more going on. Using the voice memo app to record audio gives me a waveform that gives me a real-time idea of recording level. If I shout directly into the panel with the two mics, I can get a low recording level, but nothing like using the phone's built-in mic. If I talk at a normal driving distance from the mics, the signal barely registers at all. I didn't think of disconnecting each mic in turn or both mics at the same time, but I wonder if the two mics could be faulty? It might be worth buying the two mic parts and trying them - they are super easy to fit so that might be cheaper than an OPC diagnostic that I think will be £120+ just to start the investigation.
Is there a good online source of OEM Porsche parts like that? Could those parts be shared with other VW group brands? If the mics are a few quid each I'd like to try that before wasting the OPC's time and my money! Thanks
As the diagnostic isn't going to be free, I got myself a new multimeter as my old one has gone AWOL. I pulled out the PCM head unit as you suggested and checked for continuity on all four wires, and it's there. I also checked the resistance of both mics - one is 5kOhms and the other is 6kOhms. I then opened up one microphone to find a tiny PCB with a very small IC, some tiny surface mount components and a cylindrical-shaped component with felt on one end which I am certain is the actual mic. So they aren't just simple condenser mic on wires, there's a lot more going on. Using the voice memo app to record audio gives me a waveform that gives me a real-time idea of recording level. If I shout directly into the panel with the two mics, I can get a low recording level, but nothing like using the phone's built-in mic. If I talk at a normal driving distance from the mics, the signal barely registers at all. I didn't think of disconnecting each mic in turn or both mics at the same time, but I wonder if the two mics could be faulty? It might be worth buying the two mic parts and trying them - they are super easy to fit so that might be cheaper than an OPC diagnostic that I think will be £120+ just to start the investigation.
Is there a good online source of OEM Porsche parts like that? Could those parts be shared with other VW group brands? If the mics are a few quid each I'd like to try that before wasting the OPC's time and my money! Thanks
Update - problem solved!
Popped into Ashgood Porsche to look at a beautiful Sapphire blue manual 991, but it's not an S so it's not for me. While there, I mentioned my microphone problem, and explained that if I could borrow the mics out of one of their cars, I could see if that's the problem. Vic was kind enough to let me dismantle the steering column of one of their cars, and I took the mics out and fitted them in my car. What do you know? Suddenly voice control and bluetooth handsfree all works perfectly! So I swapped my blue mic back in, and it still worked fine. Then I swapped my purple mic back in and surprise surprise, it goes back to not working. So now I've narrowed it down to the purple mic and there's no need to pay the OPC to do the diag work. Now I've just got to source the part!
Many thanks to Vic at Ashgood Porsche - I owe you a pint!
Popped into Ashgood Porsche to look at a beautiful Sapphire blue manual 991, but it's not an S so it's not for me. While there, I mentioned my microphone problem, and explained that if I could borrow the mics out of one of their cars, I could see if that's the problem. Vic was kind enough to let me dismantle the steering column of one of their cars, and I took the mics out and fitted them in my car. What do you know? Suddenly voice control and bluetooth handsfree all works perfectly! So I swapped my blue mic back in, and it still worked fine. Then I swapped my purple mic back in and surprise surprise, it goes back to not working. So now I've narrowed it down to the purple mic and there's no need to pay the OPC to do the diag work. Now I've just got to source the part!
Many thanks to Vic at Ashgood Porsche - I owe you a pint!
Thanks for the heads up Richard. I tried looking on ebay for similar mics for other VAG cars but found nothing similar - the part numbers start with 991 so that's a bit of a clue that they're Porsche specific parts.
Design 911 have a lot of electrical and audio goodies listed but no microphones, so I gave them a call hoping that at least they might know where I should go. The guy asked for my reg and he was able to load up the parts catalogue. He said there were a few revisions of the part that he could order, so I decided to go ahead and order both as I suspect that they work together as a pair for noise cancellation. I went for the latest of both so as to hopefully get a compatible pair - let's see if that works:
991.646.307.02 MICROPHONE LEFT
991.646.313.02 MICROPHONE RIGHT
My own problem mic is a 991.646.307.01:
Design 911 have a lot of electrical and audio goodies listed but no microphones, so I gave them a call hoping that at least they might know where I should go. The guy asked for my reg and he was able to load up the parts catalogue. He said there were a few revisions of the part that he could order, so I decided to go ahead and order both as I suspect that they work together as a pair for noise cancellation. I went for the latest of both so as to hopefully get a compatible pair - let's see if that works:
991.646.307.02 MICROPHONE LEFT
991.646.313.02 MICROPHONE RIGHT
My own problem mic is a 991.646.307.01:
Richard Hamilton said:
That has been superseded by 991.646.307.03. £55.85 Inc VAT from you local Porsche dealer.
I do remember discussing the .03 versions with the person i spoke to, so I was surprised when my order confirmation came through with the .02 versions. But the parts arrived an hour ago and lo and behold - they are the .03 versions. 
I've fitted them already and everything appears to be working correctly. Voice control is a *lot* more reliable now as well, although it still can't understand me when I say confirm to get rid of the disclaimer screen on startup before I can use the navigation screens. Perhaps I'll try resetting the mic volume to 0 and re-doing voice adaptation.
Thank you Richard for your assistance!
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