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Can a failed BM54 amp take out the whole audio system?


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41 replies to this topic

#1 Scotland

Scotland
  • LocationGlasgow
  • Occupation:iPhone app dev
  • Current Car:2002 540i

Posted 23 January 2013 - 06:52 PM

I think my BM54 has been flaky for a while, and last night my audio dropped dead for the 3rd time in as many months as I've owned the car. I get no sound and the DSP option eventually greys out on my nav screen. What I am wondering about though is that I can also not select my Intravee or the radio from the nav unit. Is this all just part of the BM54 dying, or is there a separate issue causing them to not work? When I plug my iPhone into the KCA-420 I also do not get any noticed of accessory connected or cannot charge or anything. I've heard xkalibar@gmail.com is the guy to get in touch with for BM54 failures, but I'm worried that my inability to access anything audio wise indicates a more serious problem!



#2 jerry528

jerry528
  • LocationGlenrothes, Fife
  • Current Car:E39 528i Sport

Posted 23 January 2013 - 07:03 PM

Check all plugs are in mate, I had the same issue last week, took all the plugs out and out them back in and it's been all good

But pretty sure if that gives up you lose what you have lost
Posted Image
Titanium Silver 528i Sport, 18" Genuine M Para's, Eibach Pro Kit,
Powerflow Exhaust, Hella Celis Rears,Hella AE Xenons with 6000K LED Markers
E39 M5 Autofold Mirrors, Intravee II & KCA-420i Alpine iPOD adapter
Widescreen Monitor & MKIII Nav Drive, Headrest DVD Monitors
Carbon Interior Trim

#3 rob-the-viking

rob-the-viking
  • LocationCambs

Posted 23 January 2013 - 09:01 PM

I'd be looking at the DSP amp failing based on those symptoms, it would seem that something is dragging the ibus down, the BM54 failing means you start to drop an individual channel or two, its unusual for t to die completely then work again the next ignition cycle. Richardp might be able to shed more light though.
Posted Image

55,573

#4 RichardP

RichardP
  • LocationNorth Yorkshire

Posted 24 January 2013 - 08:07 AM

I don't quite understand what's going on here, there appear to be multiple failures or one partial failure.

For the DSP option to grey out on the Nav menu the DSP amp must stop responding to iBus polls from the Nav.

If the radio can not be selected using the MODE or FM/AM keys or turning the radio on, then the radio is not communicating on the iBus.

If the KCA-420i is not causing the Alpine logo (or Accessory connected message) on the iPod then the Intravee is not powering up, possibly caused by no iBus messages to it.

There are two common components, power and iBus. If the iBus was down in the entire car the all sorts of odd things would start to happen, so I think this is unlikely. It may be that there is a partial iBus failure in the rear passenger side of the car, but I've never heard of this. I think the most likely is an intermittent power fault to the amp, radio and Intravee (CD Changer) but not the Nav (you'd loose all display on the monitor if the Nav and TV modules go down).
Posted Image
2003 Carbon Black E39 M5
Evolve remap, headers & race cats | Intravee II for iPod, DVD & DAB plus PXA-H100 DSP emulation | Valentine One mirror integration and head rest stealth install

#5 Scotland

Scotland
  • LocationGlasgow
  • Occupation:iPhone app dev
  • Current Car:2002 540i

Posted 24 January 2013 - 06:58 PM

Thanks for the info. How would I go about diagnosing this? I'm going to unplug the amp/make sure all other connections are secure first, but assuming that comes up with nothing, where would i go from there?



#6 RichardP

RichardP
  • LocationNorth Yorkshire

Posted 24 January 2013 - 07:30 PM

Do you have a PC connection to the Intravee, it might be able to help you.

If the Intravee is powering up the you can use it to check the status of the DSP amp and radio. Connect up the Intravee to your PC and run the downloader, as if you were going to update the firmware.

In the main window console area type the commands:

enq rad
enq dsp

After each command, if the device responds you should see some output, something like this

Device report : Radio Module BM54 MP3, Becker, P/N=06976963, Prod. Week 09/09, HW:04 SW:43

If the device is communicating and powered up it should respond, if either DSP or radio don't respond then you've found a problem.
Posted Image
2003 Carbon Black E39 M5
Evolve remap, headers & race cats | Intravee II for iPod, DVD & DAB plus PXA-H100 DSP emulation | Valentine One mirror integration and head rest stealth install

#7 Scotland

Scotland
  • LocationGlasgow
  • Occupation:iPhone app dev
  • Current Car:2002 540i

Posted 26 January 2013 - 01:17 PM

Ok I've done that just there. Both of those commands return devices, so, I guess they are being powered fine? The DSP command returns the DSP even after it has been greyed out on my nav screen, so I guess this is an iBus fault somewhere?



#8 Scotland

Scotland
  • LocationGlasgow
  • Occupation:iPhone app dev
  • Current Car:2002 540i

Posted 26 January 2013 - 01:25 PM

I just read the error codes there too. The radio is reporting an power antenna fault or something along those lines, and the widecscreen monitor is reporting radio status telegramm timeout (which I assuming is the lack of response to the polling you are talking about, and watchdog reset? Not read all the error memories I could have but possibly getting somewhere now



#9 RichardP

RichardP
  • LocationNorth Yorkshire

Posted 26 January 2013 - 01:59 PM

If you can take an iBus log with the Intravee of the DSP option greying out or radio not being selectable, I might be able to see what's missing. Thw whole relationship between Nav, Monitor, Radio, DSP, CD Changer, Phone, VR and TV is quite complex.
Posted Image
2003 Carbon Black E39 M5
Evolve remap, headers & race cats | Intravee II for iPod, DVD & DAB plus PXA-H100 DSP emulation | Valentine One mirror integration and head rest stealth install

#10 Scotland

Scotland
  • LocationGlasgow
  • Occupation:iPhone app dev
  • Current Car:2002 540i

Posted 26 January 2013 - 02:21 PM

I followed the instructions from your other thread about emulating commands etc, sorry if this isn't what you wanted!

Attached Files



#11 RichardP

RichardP
  • LocationNorth Yorkshire

Posted 26 January 2013 - 02:48 PM

There are no messages from the DSP amp in that log, which indicates that it's the probable cause.

Both the radio and the Nav should poll the DSP amp for it's status at regular intervals, the Nav (or Graphics driver to be more accurate) every 50 seconds, the radio every 20 seconds. Both of the poll messages are in your log, for example

from the Nav
IBUS: 00:12:02.86 3B 03 6A 01 53 [53]

from the radio
IBUS: 00:12:21.19 68 03 6A 01 00 [00]

The DSP amp should respond to both with
6A 04 FF 02 00 93

but this never appears in your log.

So, I think the DSP amp is faulty and not responding correctly.
Posted Image
2003 Carbon Black E39 M5
Evolve remap, headers & race cats | Intravee II for iPod, DVD & DAB plus PXA-H100 DSP emulation | Valentine One mirror integration and head rest stealth install

#12 Scotland

Scotland
  • LocationGlasgow
  • Occupation:iPhone app dev
  • Current Car:2002 540i

Posted 26 January 2013 - 03:15 PM

Excellent! Thanks so much for all your help. Am I better off getting an aftermarket replacement, or would that be more hassle than just swapping in another DSP amp? I'm not so concerned about audio quality etc, just that it all works!



#13 RichardP

RichardP
  • LocationNorth Yorkshire

Posted 26 January 2013 - 03:39 PM

It's not dead straight forwards to replace the DSP amp with something else.

The problem is that all the crossovers are built into the DSP amp, so you can't just and an amp and plug it in, you'll blow the tweeters.

The nearest to a plug and play option I know of is the JBL MS8, but there is still a reasonable amount of setup required.

Another option as you already have an Intravee would be an Alpine PXA-H100 or H800 and some amps, with the H100 you'll need some extra crossovers unless you also start replacing speakers or decide you don't need the rears - you would run the H100 in three way mode and keep the front mids and tweeters plus the subs, you'd need a 5 or 6 channel amp (or amps) as well.
Posted Image
2003 Carbon Black E39 M5
Evolve remap, headers & race cats | Intravee II for iPod, DVD & DAB plus PXA-H100 DSP emulation | Valentine One mirror integration and head rest stealth install

#14 Scotland

Scotland
  • LocationGlasgow
  • Occupation:iPhone app dev
  • Current Car:2002 540i

Posted 26 January 2013 - 03:55 PM

So just so I understand, I can't even swap in another BMW DSP amp with blowing the speakers, or does that just apply for aftermarket amps?



#15 RichardP

RichardP
  • LocationNorth Yorkshire

Posted 26 January 2013 - 04:18 PM

You can plug in another BMW DSP amp, it's just after market amps that don't have the crosovers, but it will probably need to be coded to get the correct frequency response for the car, unless it's out of an identical car.
Posted Image
2003 Carbon Black E39 M5
Evolve remap, headers & race cats | Intravee II for iPod, DVD & DAB plus PXA-H100 DSP emulation | Valentine One mirror integration and head rest stealth install

#16 Scotland

Scotland
  • LocationGlasgow
  • Occupation:iPhone app dev
  • Current Car:2002 540i

Posted 26 January 2013 - 05:16 PM

Excellent. Were the DSP amps the same across all models/years? I see this on ebay http://www.ebay.co.u...d=370723771846 but it says it's from a 740 so just checking. I'll double check the part number on mine just now



#17 RichardP

RichardP
  • LocationNorth Yorkshire

Posted 26 January 2013 - 06:53 PM

I believe they are basically the same, but there are different versions of the amp made by different manufacturers, Philips, Lear, Alpine ... Some are better then others, I 'think' I've read that Lear are better, but it would be worth a quick search.
Posted Image
2003 Carbon Black E39 M5
Evolve remap, headers & race cats | Intravee II for iPod, DVD & DAB plus PXA-H100 DSP emulation | Valentine One mirror integration and head rest stealth install

#18 Scotland

Scotland
  • LocationGlasgow
  • Occupation:iPhone app dev
  • Current Car:2002 540i

Posted 26 January 2013 - 08:40 PM

I've managed to pull my DSP amp out and I've got a Lear one. Does anyone do repairs of these, and can you bypass the DSP for the time being, and have DSPless sound?



#19 rob-the-viking

rob-the-viking
  • LocationCambs

Posted 27 January 2013 - 08:04 AM

Holy smokes, it would seem my hunch was correct. I'm not sure about repairs to DSP amps, they're not a common failing like the BM54. You might be better sourcing a second hand one, I believe it will need coding to the car though, which is relatively easy if you have NCS expert.
Posted Image

55,573

#20 RichardP

RichardP
  • LocationNorth Yorkshire

Posted 27 January 2013 - 09:24 AM

I've managed to pull my DSP amp out and I've got a Lear one. Does anyone do repairs of these, and can you bypass the DSP for the time being, and have DSPless sound?

You could ask XKaLiBaR, he repairs the radios and upgrades their components.

Bypassing DSP is not easy due to the active crossover. You could get a very temporary solution by connecting the outputs of the radio to the mid/bass units. You'll be way down on the top end, but you will have sound.
Posted Image
2003 Carbon Black E39 M5
Evolve remap, headers & race cats | Intravee II for iPod, DVD & DAB plus PXA-H100 DSP emulation | Valentine One mirror integration and head rest stealth install

#21 XKaLiBaR

XKaLiBaR
  • LocationEnfield
  • Current Car:E46 M3 & E39

Posted 27 January 2013 - 06:09 PM

From the symptoms described, the bm54 is dead, or more technical terms, its not powering on. Ergo, the DSP is not getting switched on, and displays the DSP option on the screen in grey.

 

Im just with a customer, I will email you back in an hour or so. 



#22 RichardP

RichardP
  • LocationNorth Yorkshire

Posted 27 January 2013 - 06:15 PM

But that scenario does not explain why the iBus log shows messages from the radio and Nav, including polls to the DSP system, and no messages from the DSP amp, including poll responses.

The only case under which a faulty radio would explain the above is if the radio controls the switched line to the DSP amp and it's not becoming live. The DSP amp is not turned on by a specific iBus command from the radio.
Posted Image
2003 Carbon Black E39 M5
Evolve remap, headers & race cats | Intravee II for iPod, DVD & DAB plus PXA-H100 DSP emulation | Valentine One mirror integration and head rest stealth install

#23 XKaLiBaR

XKaLiBaR
  • LocationEnfield
  • Current Car:E46 M3 & E39

Posted 27 January 2013 - 06:59 PM

The fact that he has no orange light and control over the left side, indicates the bm54 is not powering up. If the bm54 is not powering up, then the DSP is not powering up, because the 12v remote from the bm54 that goes to the dsp, won't be producing any power.

The ibus signals in this case are irrelevant, trust me. Don't forget, the bm54 is still getting 12v sent into it, and the ibus signal. So parts of it might be working to send the signal you are referring to, but it's not switching on properly.

If it is an old bm54, I have more chance of bringing it back to life, than the newer units.

Just thought of another reason why you might be getting ibus signal, the older units seem to come on without sending an ibus signal. Hard to explain, but that could explain that.

#24 RichardP

RichardP
  • LocationNorth Yorkshire

Posted 27 January 2013 - 07:33 PM

Well, I don;t know the BM54 as well as you Baris, but if there is an issue with the power on line from the radio to the DSP amp, it would be simple to either check for power on the output of the radio or apply power directly to the switched power pin on the amp to see if it turns on. The only power line that I know is controlled by the radio is pin 13, antenna out.
Posted Image
2003 Carbon Black E39 M5
Evolve remap, headers & race cats | Intravee II for iPod, DVD & DAB plus PXA-H100 DSP emulation | Valentine One mirror integration and head rest stealth install

#25 XKaLiBaR

XKaLiBaR
  • LocationEnfield
  • Current Car:E46 M3 & E39

Posted 27 January 2013 - 08:11 PM

Sometimes pin 13 produces less than 12v, resulting in the bm54 still fully working, but not powering the DSP on. But thats all irrelevant, if the you lost all power to the left side of the screen. 

 

The DSP amp doesnt fail as much on the BMWs. More on the Range Rovers, due to the way it is located. 

 

Edit: The BM54 is more reliable on land rovers than X5, again due to the bad location of the bm54 in the x5. 


Edited by XKaLiBaR, 27 January 2013 - 09:21 PM.


#26 Scotland

Scotland
  • LocationGlasgow
  • Occupation:iPhone app dev
  • Current Car:2002 540i

Posted 28 January 2013 - 06:20 PM

Thanks for all your help guys, but in the interests of narrowing the problem down a bit more, I noticed when i jumped in the car today that the DSP option was gone from the screen right after turning the key, and came back a split second later, so I take this to mean something sound wise is responding to polls albeit briefly?



#27 RichardP

RichardP
  • LocationNorth Yorkshire

Posted 29 January 2013 - 07:02 AM

Well, if it's what Baris suggests, the radio not providing enough voltage to turn on the DSP amp, then it's possible that it's marginal. Sometimes just enough, sometimes just not enough. Do you have a multimeter that you could use to measure the output of pin 13 from the radio?
Posted Image
2003 Carbon Black E39 M5
Evolve remap, headers & race cats | Intravee II for iPod, DVD & DAB plus PXA-H100 DSP emulation | Valentine One mirror integration and head rest stealth install

#28 Scotland

Scotland
  • LocationGlasgow
  • Occupation:iPhone app dev
  • Current Car:2002 540i

Posted 29 January 2013 - 05:55 PM

Yep I do. Got a diagram for where pin 13 is? and by radio do you mean the BM54?



#29 XKaLiBaR

XKaLiBaR
  • LocationEnfield
  • Current Car:E46 M3 & E39

Posted 29 January 2013 - 07:19 PM

Pin 13 is the wire coming out next to where the fuse is on the bm54. I think it's white and yellow cable.

Sometimes, it might produce 12v, even though the bm54 is not powering on, but it's rare.

#30 Scotland

Scotland
  • LocationGlasgow
  • Occupation:iPhone app dev
  • Current Car:2002 540i

Posted 29 January 2013 - 08:23 PM

Sorry for the potentially stupid question, but I'm assuming power comes into the BM54 via the same plug that pin 13 is in, and so I'm assuming I'll need to yank that wire out of the plug to get a voltmeter in-between? or is there an easier way to do it?






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