[mcscoobs]

Got in the car this morning, screen was working fine, but no audio from the radio. Screen keep skipping to “Attention - No warning tones” every 5/6 seconds. I get no audio from radio, my phone, parking sensors, nothing at all.

Any ideas where to start, before I take it to BMW for them to charge me a fortune?

[Billfitz]

Step 1: Pull Codes. That's the first thing BMW will do, but they don't do it for free.

[NealfromNZ]

No warning tones is when when HK audio systems using Most Fibre system has an interruption or break in the Idrive / cluster / amp chain.

Typically it’s because the idrive doesn’t see the amplifier but the system is a fibre optic loop between idrive , instrument cluster and amp in trunk. The cable it’s self is two green plastic cables that have one connected at the amp, one into the idrive and one into the cluster. There is a junction connector clipped onto the back of the hvac unit behind idrive unit in the center console. The function to amp fibre optical cable is routed at the back of the firewall and down the left hand side of the car.

Any break of those cable can cause the issue.

The other is that the HK amp is or has gone faulty with the most common issue being water entering the area were the amp is located through pressure washing around the rear bumper or the tail light area being gunked up causing water to enter trunk. The amp gets submerged as the area has no natural water drainage.

Do the basics of checking the fuses in the rear fuse box under the trunk floor. Look for any associated with infotainment.

Then do a reboot of the idrive by pushing and holding down the volume knob for 30- 40 seconds.

From there I’d inspect the amp for water damage but removing left hand trim lining.

Fault codes may tell to which device it is or just basically say Most bus error.

Anyway, here a starting point.

[mcscoobs]

Turns out it was the amp - the dog tipped over some water that was in the boot (to clean him after a muddy walk) - the amp was water damaged. Been sent off for repair - much cheaper than buying a replacement anyway!

[Goddard]

Originally Posted by mcscoobs

Turns out it was the amp - the dog tipped over some water that was in the boot (to clean him after a muddy walk) - the amp was water damaged. Been sent off for repair - much cheaper than buying a replacement anyway!

I have the same issue with my 330d. Where have you sent it for repair and how much did it cost you mate?
Cheers.

[mcscoobs]

Went through Cartronics… £850!