MMI not removing mute!

[RUM4MO]

Once or twice recently I have become aware that when starting the car, the radio was muted, not a big issue but what is going on I wondered. Today after travelling for 26 miles with few Start/Stop which I allowed to happen as the traffic lights had caught me, we stopped to shop for 20 minutes, on our return to the car and starting it up, I was unable to "unmute" the muted - and not by me, radio! Switching the unit off and on a few times did nothing, the inside of the car was still warm although the outside temperature was 3.5>2.5C! After leaving the MMI off during most of the 16 miles journey back home, I switched it back on just after driving down my driveway, the radio was unmuted, I tried MUTE, it muted, I pressed MUTE again it unmuted.

So, I scanned the car and found no logged faults with the MMi, when I initially spotted this issue and failed to get the sound back, I tried using the volume controls on the steering wheel and that only forced the small centre display area to show the volume with no volume, just a thin line.

Has anyone else had this issue and if so, what did VW do to stop this happening, the "action" or "feel" of the MUTE button on the MMI feels like it has always done, ie "okay".

Edit:- changed or corrected the subject title!

[iichel]

i'm assuming we're talking about your wifes polo 6C SEL? with discover media system?

[RUM4MO]

Hum, well the one without Nav, never worked out which one it is, CD player and maybe SD card socket in the glovebox, but yes the Polo SEL 6C.

[alexperkins]

It might need a software update. Probably a visit to the dealer

[RUM4MO]

Thanks Alex, oh bother!

[RUM4MO]

It might need a software update. Probably a visit to the dealer

One thing that springs to mind is, as this has happened again, and I think that it is only happening if I had the sound muted, in radio as signal source and I've driven into an area with poor/no radio reception for that selcted station. I've have tried, a previous time when this happened and probably in an area with no radio signal, getting my wife to stuff a CD into the player - still unable to remove mute even when CD player selected.

So, maybe this issue has been discovered and resolved with a S/W update?

[veteran]

Rum4mo,

Here's something to ask yourself. Do appreciate, I'm being a devil's advocate here.

Prior to the mute becoming un-mutable, were you listening on the radio via DAB, or was it FM? If DAB and the signal strength was very low in that place, then the station might very well have disappeared from capture. Digital broadcast signals 'fall off a cliff-edge' if, at the receiver, the signal strength is below the capture level. If the station's strength weren't within capture, therefore, it'd be like it was turned off - completely muted, in other words. With FM, on the other hand, there's no cliff-edge effect and instead the signal-to-noise ratio simply degrades, and fluttering thereafter ensues.

This wouldn't explain why the CD player wouldn't unmute, however. But when switching to CD or SD playing, from radio, is there a need to go into the Media button menu first, or should the switching be automatic on insertion of the disc?

I've noted that, in my 11.2016 edition of the 'Composition Media, Discover Media (Generation 2)' VW booklet that gives some operating info on the Infotainment system that it's stated that 'when the temperature inside the Infotainment system is too high, loading and playback of CDs is disabled'. I presume that you were able to load a CD but that it then wouldn't play, as if muted? Remember, this is as stated as per 11.2016. It's possible that a software modification in respect of this was added between 2015 (when you first acquired your Polo) and November 2016.

If your problem isn't down to a purely DAB signal-strength matter, then it does rather look as though it could be temperature-related, doesn't it? Presumably, you had the heating system on when travelling, and maybe even playing the radio at high volume as well (which then would have heated up the Infotainment unit)? But the return journey may have caused the stored heat to gradually dissipate.

[SRGTD]

Rum4mo,

Here's something to ask yourself. Do appreciate, I'm being a devil's advocate here.

Prior to the mute becoming un-mutable, were you listening on the radio via DAB, or was it FM? If DAB and the signal strength was very low in that place, then the station might very well have disappeared from capture. Digital broadcast signals 'fall off a cliff-edge' if, at the receiver, the signal strength is below the capture level. If the station's strength weren't within capture, therefore, it'd be like it was turned off - completely muted, in other words. With FM, on the other hand, there's no cliff-edge effect and instead the signal-to-noise ratio simply degrades, and fluttering thereafter ensues.

I have the Composition Media unit in my Polo. On the few occasions that my unit has lost the DAB signal, the radio station I had been listening to automatically switched to that same station on the FM band. I think this is how it’s meant to work (I’ve read on other forums that Golf owners with MIB2 infotainment units have had this happen where the DAB signal is lost). This being so, weak DAB signal probably isn’t the reason for RUM4MO’s muting problem.

[veteran]

SRGTD,

Yeh, I'd agree with that. I didn't appreciate that they'd switch, so thanks for pointing that out. I'll try to keep that in mind for the future.

Does it work like that the other way around? For instance, if you're listening on FM and the signal becomes weak, does it attempt to switch to DAB? I myself normally listen on FM, in the car.

[SRGTD]

Good question! I honestly don’t know.

If I remember, the next time it auto-switches from DAB to FM, I’ll leave it on FM and see if it does auto switch back to DAB if/when the DAB signal improves.

[RUM4MO]

My main problem is that I'm never knowingly noticing the radio signal dropping because I've already muted the MMI, it is only when I decide to actually listen to the radio - or any other signal source, that I can't get the "muted" symbol to disappear, it is not that I can't start hearing something - which is what I'm wanting to do, but more the issue that the muted symbol can not be removed, if there was no radio signal at that point, and the same with the alternative wavelength as suggested, then surely I could still remove the mute function and in doing so make the muted symbol disappear - although I'd still be left with no noise coming out of the speakers, which is both understandable and acceptable if I'm in a radio black spot.

[veteran]

On mine, I can't recall ever seeing a 'muted' symbol when it's in that supposedly muted state. But perhaps I've never truly noticed. That's now something I'll check out on mine.

If I've fully understood what you've now added, namely that it's not about not hearing something, but that you can't get the muted symbol to go away when you've unmuted, then surely that points more toward it being a software bug, albeit a minor one, doesn't it?

[veteran]

I thought I'd try googling for 'VW Polo software updates'. I found something called "New software update in VW Polo - YouTube", with the YouTube video dated as 31st July 2017. I've not viewed it yet but that might indicate something useful, Rum4Mo.

On the Web I've also noticed that certain software updates are also available from a Volkswagen site in Germany, the updates being owner-performable. However, when investigated I found that these were only for navigation systems built into infotainment systems on various VW's. They relate principally to updates to roadmap databases.

[RUM4MO]

The mute symbol is not something that you would necessary notice unless you were having issues and start looking for reason why, it is a small speaker symbol with a diagonal line through it and it appears when mute is on, at the top of the MMI screen. Also, on the small display between the dials, when you change the volume level, you get a bar showing at the top of that small display showing the present level wrt the maximum level, when mute is on, changing the volume level obviously does nothing and on that small display between the dials the present volume, shown as a proportion of max volume, is displayed as effectively zero volume - which is understandable.

Well last night we were out for a meal at friends who live quite a few miles beyond the section of road where I have been experiencing this inability to remove mute from the MMI while radio - FM or DAB is selected and Radio 2 as the chosen station - and so I started our journey from home with Radio 2 on, it stayed on for that complete journey, did the same coming home, although I did mute and removed mute a few times on the way home mainly when I thought that I was on the section of road "of interest"!

I've not checked MMI S/W version yet, though I'm be very sure that a 2017 car would have a newer version of S/W as nothing in the S/W world stands still!

So, more work to do for me it seems.

[RUM4MO]

Here is some info on the MMI system fitted to my wife's August 2015 build Polo SEL:- Device part number: 3Q0035820 Hardware: H11 Software: 0138

I see there is a "Update software" option at the bottom of that screen.