X5 F15 "No warning tones" - odd one

[LordNelson]

Hi all. Bit of an issue which I've read about lots but not come across a concrete answer.

I have the HK system in my F15 (with pronav) and got the "no warning tones" notice along with complete loss of sounds and use of buttons relating.
The radio was still working, albeit silently, as well as the satnav etc.

After much forum trawling I tried to find the fault in the optical cable, but struggled.
I pulled every fuse to check for anything blown. All seemed OK, but also learned the American fuse boards are different to the UK. Not helpful.

Then, after a long sunny day, I got in a very hot car and by some fluke it all worked again. Perfectly.
But the day after, all gone again. Gutted.
It has done this a cpl of times now, suggesting a bad connection.

My question is, has anyone had this before?
Where do I start looking for a bad connection? Head unit, amp, speakers??
Can fuses be affected by the heat?

Any help much appreciated.
Thanks.

[jfandl]

I had the same problem thanks to a sunroof drain blockage that caused water to fall on my amp in the left rear trunk.
Search Amazon for: "Universal Most Fiber Optic Optical Loop Bypass Female Adapter"
Link (if it works): https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

You'll have to cut off part of the plastic to make it work but basically you're making a loop jumper to bypass the amp. This will tell you if the AMP has failed or not.

If it has failed, you might want to upgrade to a BAV sound amp. It's pricey (look for clearance sales) but it's a huge upgrade over the factory amp.

[Jolliness9825]

Hello all and didn't mean to hijack the thread, but i'm having same issue as OP.
However, I took it in for diag at the dealership($200 for diag..), and gave me the result and estimates.

Result from the tech:
- AMP is not getting power from power source.
- Found 50 AMP fuse on top of battery blown.
Recommendation:
- Replace and Program AMP and Fuse Block on top of battery.

Estimate of cost: $3200

So, I open up the AMP area(Left-side of the trunk), and took a picture of it... It seems to me that it's getting a power.. Please see the attachment of picture. That's what I have when the car is in accessory mode.

My own diag:
- Head unit seems to be working(No Audio. No notification tone/Warning tone).
I am able to:
- Radio works, I can change band between AM/FM/SATELLITE/BLUETOOTH
- Bluetooh, I'm able to pair it with my phone, but no audio
- Satellite, I can change channels, but no audio.
- Navigation, I can set destination, and navigate, but no audio.

- Checked Fuses in fuse block in right-side of trunk, and under the glovebox.
- All fuses related to Media/Audio are in good state. not noticing any sign of blown.

My attempts but need your opinion/suggestions before act on it:
- It seems the fuse tech mentioned is NOT replaceable. So, I think I need to change entire fuse block(Used from eBay, in between $40 - $60). Can I replace the fuse block(one that on top of battery) by myself?

I'm not still sure if my attempts would remediate the issue or not...
Any suggestions and ideas from you would much be appreciated...

Thanks much!