Only 40 Seconds of Radio

[Patrick-Irish]

Hi,

Sometimes (occasionally) the radio in my X5 acts funny. I don't know if it's broken or if there's a button I've hit by accident.

Turn on the radio and it'll stay on for exactly 40 seconds. Then - silence. Changing the channel does nothing. The display shows the channel has been changed, in fact everything looks normal like there's nothing wrong.

But again - 40 seconds and the sound goes. Turn the radio off then on again, 40 seconds later - silence. Over an over again. Always 40 seconds exactly.

Anyone got any idea what's going on ?

[bimmer_buachaill]

What year? 40 seconds exactly is very odd.

Is it possible your battery is low voltage or did you replace it recently? Does it only show fault after the car has been sitting idle for a long time? No other electrical issues at all?

[Patrick-Irish]

Hi,

No the battery is putting out the correct voltage and hasn't been replaced recently. And no other electrical problems are apparent. It's a 2001 X5 model.

40 seconds it is, on the button every time. It leads me to believe there may be some setting or other in the background triggering the 40 second shut-down for some reason.

There again, last night when I parked up this was happening. And when I started up this morning, no problem. The radio stays on.

Odd. I tell ya, there are gremlins in BMW electrics !

[Patrick-Irish]

Hi,

No the battery is putting out the correct voltage and hasn't been replaced recently. And no other electrical problems are apparent. It's a 2001 X5 model.

40 seconds it is, on the button every time. It leads me to believe there may be some setting or other in the background triggering the 40 second shut-down for some reason.

There again, last night when I parked up this was happening. And when I started up this morning, no problem. The radio stays on.

Odd. I tell ya, there are gremlins in BMW electrics !

[Laurence]

Do you have a DSP setup by any chance?

[Patrick-Irish]

Yes - it does have the DSP thingy .....

[Laurence]

OK, when the radio goes silent, have a look at the DSP setting on the main menu, can you access the DSP menu or is it greyed out?

[Patrick-Irish]

Erm ..... dunno. I hadn't tried accessing the DSP menu when the sound goes. I'll try that next time. What does it mean if it's greyed out ?

[Laurence]

I had a similar problem to you, radio sound (and CD) would stop after 40 seconds. If I stopped the car and turned the ignition off it would all work again, sometimes for 40 seconds only, other times it would work all the time.

I'll try to explain what happened, but it’s really stretching my knowledge of how the car works!
The DSP provides all amplification to the car – so the Radio feeds the DSP witch then amplifies the sound to the speakers.
All of these components are controlled by the i-bus, this provides communication between all devices and controls how the devices operate – for every button press etc etc.
As part of this communication process, every device is polled to make sure its alive and that it can be communicated with.
In my situation, it appeared that the DSP was not responding to any i-bus communication, if it fails to reply to the polling, the car thinks it is not there.
If the car thinks the DSP is “not there” it will grey out the display on the sat screen and, if the DSP thinks its not connected as it hasn’t received any polling requests from the i-bus it shuts itself down – end result no amplification and no audio. (This may not be exactly how the i-bus works, but its my understanding - I'm sure someone will put me straight!)

Its worth checking all the connections to the DSP amplifier and maybe reseating them – that may be sufficient to get it back up and running. Also check that none of the cables are shorting to ground as this could stop i-bus communication.
I reseated my connections to the DSP and I’ve not had a problem for a while now.

[bimmer_buachaill]

Sounds like Laurence has it nailed down. Good luck Patrick (from a Wexford man).