I installed a new battery yesterday and didn't have any sound from the radio, CD, SAT, AUX, parking assist or anything. Everything displayed as normal and the volume indicator went up as though there was sound.

It was as though it was stuck in mute or the phone connection mode.

I have a 2009 XF with factory head unit and aftermarket Hertz speakers and crossovers with a JBL amp and JBL subs.

I tried all of the tricks from past posts but none worked.

So I accessed the factory unit in the trunk on the drivers side and pulled this optical plug and reconnected it and the sound came on immediately. So I thought I would share in case anyone else had this issue.

 

I may of celebrated too early. Apparently it allowed me to have very basic sound straight from the radio minus any amps. Only the center dash speaker and rear deck speakers plays sound. The parking assist and touch screen beeps don't play at all.

 

Anyone knows what this wire is for?

 

Yep.
It's used by the dealership to complete the new car pre-delivery set up (plugged into the SDD wotsit), and is never used or needed again.
So bad luck, it's nothing to do with your Simon & Garfunkel problem!

 

I would try a hard reset and if that doesn't have any affect then unplug all of the aftermarket additions and try another reset. It probably goes without saying to inspect all wiring you can get to, including anything you can access around the steering wheel if you think it could be something to do with the voice command prompt stuck on. Electrical trouble shooting is the worst!

 

When you say hard reset, I'm assuming you mean disconnect and reconnect the battery?

 

Disconnect the negative lead from the battery and hold it to the positive lead for 10 seconds, then reconnect. It will erase all data stored in memory including some radio functions (including the radio code if your car requires one), window stop limits, etc. If you want to read more about it, search the forum and you may find exactly what it will do for your year/model.

 

I did that yesterday with no luck. Last night I put the battery on a charger to play it safe even though it's a brand new battery.

 

So last night I disconnected the battery and left it disconnected over night. I connected the positive and negative cables together and left them connected overnight.

I also pulled and tested all fuses from all three fuse boxes. All of the fuses were good. I did replace 2 of them from the fuse box in the engine compartment because I think the heat warped them a bit although they were still functioning.

This morning I connected the battery by connecting the positive side first and then connecting the negative side really fast as not to cause any sparks.

No change. I was as though I never did all of that work

I think the next step will be to by a used factory amp off of Ebay to see if that resolves the issue.

 

Is the fuse highlighted in yellow for the amp? If not, which on is the correct one?

 

I ordered a replacement factory amp yesterday and hopefully it will arrive by the weekend.

I'm trying to think about this logically, I'm assuming the sound bypassing the factory amp and the aftermarket amp is tied to the PLII option being greyed out in SETTINGS under Audio on the factory head unit. I understand the head unit is a possible source of the issue but my first path will go off of the assumption that the head unit only gives you the option to choose which sound option you want (stereo, 3 Channel or PLII) but the factory amp has the components needed to deliver each of the 3 sound options.

So I'm going down the path that something within the amp stopped working for the PLII option and preventing sound to be delivered from the OUT side of the factory amp.

 

I connected my mobile phone up to the AUX inputs on the Bit Ten digital processor to play Pandora through it but no sound came out and the lights didn't even flicker that confirms sound is flowing through. I then moved to the next component in the chain which is the aftermarket amp and connected my phone up directly into the amp and beautiful music once again flowed through my speakers. So right now I will focus on the factory amp and the Bit Ten processor as the suspects. I will begin reading the instruction manual for the Bit Ten processor to have a better understanding of how it works in case the replacement factory amp doesn't resolve the issue.

 

Problem solved

I downloaded the software for the Bit Ten processor onto my laptop, connected my laptop to the Bit Ten processor and ran it through the 'new install' procedures.

After several tries I was unsuccessful and was just about to give up when I decided to mess with the manual controls on the program (although the instructions tell you not to).

I noticed the volume button was set to almost zero, so I raised the level to about 80% and my beautiful sound started flowing through my speakers again.

So in the end this was more of an aftermarket component issue rather than a Jag issue.

Now it's time for a beer.

 

So glad you solved this.

Thanks for an interesting read.

 

Nice work troubleshooting! Enjoy your new tunes.