Help with sound system.

[Imtryingtofixit]

I'm having trouble with my sounds system. It has the audi multimedia and i belive the standard sound system. Mmi turns on. All the buttons work, even the volume knob. I tested the resistance on it, and I can see it mutes when brought all the way down. I tested the speakers at the amp, and all of them have resistance, so there are no blown speakers. The amp is getting proper voltage. I went into the sound system on my launch scan tool, and when I went to actuate the speakers, they all came to life. Didn't even go through the actual actuation test. I disconnected the scan tool and turned off the car. When I turned it back on, they were no longer working again. I did the same thing, and again, they started working. I'm thinking maybe the module is faulty, but I'm not sure. Also, where is that module? Any help is appreciated.

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UPDATE while I was typing this out, I left the scan tool on the sounds system module open, and when I looked down, it said it lost communication with the module. Speakers were still working though. Turned off again to test, and once again, they had stopped working.

[Imtryingtofixit]

Is this discrimination against my launch scantool?

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This was my form of comedy

[Smac770]

You don't ever say what your actual problem is. Just "having trouble".
You don't say what infotainment system front end you have. Does the unit above the climate controls say Audi multimedia or Audi concert?
You don't say what sound system back end you have. Is this the standard sound system or the B&O sound system?

[Imtryingtofixit]

You are absolutely right. Sorry about that. Since I know next to nothing about sound systems, I didn't even realize that they could work differently until i went to the junkyard yesterday. I have the audi multimedia, and I believe it's standard. I haven't seen anything indicating otherwise. Thank you

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[Smac770]

"Audi multimedia" on the dash unit would be the MMI 3G infotainment system. This is the system that has the controls around the gear shifter, and uses the optical MOST ring for module connectivity.
B&O sound system, if you have that, there will be round metal rings saying Bang & Olufsen on the front door sail cards. If the sail cards appear to just be black molded plastic, then the standard sound system.
So the issue is lack of sound from the speakers, but only at some times. Other times, everything plays like you'd expect?
MMI 3G with standard sound system is going to have only the radio unit with integrated amp in the back left corner. So there's only three MOST units involved: the J533 gateway (what connects the MOST ring to the rest of the car), the J794 MMI 3G module (the unit in the dash that says Audi multimedia), and the radio unit (with integrated 6-ch amp). So pretty simple. You don't have any error codes from 56-radio or 5F-infotainment?
Does the back left corner appear to have any water intrusion?
"I went to actuate the speakers", that's not a process flow description. So you ran an output test on 56-radio? Or you simply had the tool connected and was just playing the normal audio?
Best random guess at this point is your radio has water damage and is flaking out.
You never say what model year Q5 this is.

[Imtryingtofixit]

It's a 2010 audi q5 quattro. I went into the module labeled sound system on the scantool and clicked on the actuation portion of the module. There, it gives me the options to test the speakers. Once I go into the actual test and finish, then and only then do my speakers start working after I turn off the vehicle, they go dead again. And won't work until I repeat those actions. I checked again to see if I had the standard or not, and I think I was wrong. I believe it is B&O. I'll be attaching pictures. I hope they show. Also, there are no codes in the radio. I do have one in the comfort system for the alarm horn, but I don't know if it is intertwined with the sounds system. I did check the amp to see if I was getting current, and I didn't see anything that would indicate water was there. Thank you once again

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[Smac770]

function 03, ok, that's called output test in VCDS. https://www.ross-tech.com/vcds/tour/open_screen.php

You have a J525 at 47-sound system. So you must have the B&O sound system, as confirmed by the dash trim. 8T0 035 223 H, that was used for 9VK (B&O) through end of Oct '09, then replaced by revision AL starting Nov '09 for the remainder of MY10. MY11/MY12 used revision AN.

The alarm horn is a LIN bus slave of the J393 (46-central convenience aka central comfort). It has no cross with the sound system.

Is the issue the same whether you have the radio input selected or using a media input like the CD player, SD card slot, or AMI port? The radio is handled by the radio in the left rear with the amp, but all media is handled by the J794 in the dash. If it's the same across the board, then at least it would seem to be an issue limited to the amp unit. I don't have any speculations on why the amp would appear to sleep unless it's being directly queried (such as with a scan tool).

If you just get in the car, no need to turn on ignition or anything, and press the volume button to turn on the infotainment system, the screen should come on and the MMI should be interactive. You get no audio at that point. But if you hook up the scan tool and go to say just 19-gateway, don't go to the amp or radio or 5F, does the audio start working then? What if you go to 56-radio? Or is it only when you go directly to 47-sound system? And then the speakers play whatever selected audio source you have just fine?

Very odd issue. That there's no codes, something seems "misconfigured", but I have no speculation as to what it could be. Even when my J525 was flaking out (no speaker output, but it would still interact on the MOST ring), I had a code for a power supply issue in the J525.

[Imtryingtofixit]

Yeah, the no codes is what really stumped me. I've tried with the cd and with calls, and still no audio. I don't have an SD card to try that. I tried doing the same process with the 56-radio, and it said the action wasn't available. (This was in the morning) I'll try with other modules just in case and get back to you tomorrow morning.

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[Smac770]

CD and handsfree, that's enough to clarify it's not an issue specific to the radio unit. The common unit seems to to be the amp, as it's what drives the speakers. I don't know if MMI 3G radio unit has any output tests mode to access. I have MMI 2G.

If you just sleep the infotainment system and wake it, do you get speaker output? Press the volume knob (like you were muting it) and hold that for several seconds until you see the screen go off. Then press the volume knob again to wake the system back up.

[Imtryingtofixit]

Sorry for the late reply. It's been a hectic day. I was able to try with the other modules aforementioned above, and it seems it only works when I go into the sound system module. Sleeping the unit does not produce any sounds. If it is the amp, can I get one at the junkyard? Will the component protection activate?

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[Smac770]

A new to vehicle amp will have CP active. That would need to be reset. Or you'd need to open up the amps and move the CP chip over. That's been done, stuff out there on youtube and elsewhere of moving over the CP chip.

Only other thing I can think of would be to reboot the MMI 3G system. https://mr-fix.info/audi-mmi-force-r...-reboot-2g-3g/

There was no precursor to this issue? Just started out of the blue?

[Imtryingtofixit]

I recently bought it for my wife and I didn't even think to check the speakers when I bought it. So I have no idea if there was a precursor to it or not. The reboot is the first thing i tried before i even started digging into it. I'll try to get an amp as soon as I can and get back to you. Honestly I bought a radio at the junkyard to try to test and see if it would make any kind of sound at all so I have to go and return that joint.

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[Smac770]

I don't know what the MMI 3G B&O amp CP exhibit is. For my MMI 2G B&O amp, it only plays through the left side speakers since CP is active. I think for MMI 3G, it might be it cuts in and out or doesn't play at all. But that's only for "entertainment sources". It's still going to play handsfree phone calls correctly even with CP active. So if you replace the amp with a known good one, you can still use that to confirm a change in behavior vs your current amp. If the new replacement also has no sound for the handsfree source, then it's more likely something else. If you get an alternative amp to try, it needs to be an 8T0...H or 8T0...AL.

[Imtryingtofixit]

Does the amp have to come from a q5, Or can I pull the amp from any as long as the plugs are the same?

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[Smac770]

It only needs to be the correct p/n, from whatever it comes from. The DSP parameters for your VIN can be loaded from the Audi servers when you have the CP reset. But you're going to find that the H and AL revs were only used in MY09 and MY10 Q5s. Whereas my MMI 2G rev T was used in MY08 and MY09 A5 coupes and MY09 A4 sedan/avant.