2008 550i - Buzzing behind fuse panel above battery. Shorting?

[Jay550]

Hi and thanks for reading,


A few weeks ago (on my beloved 2008 E60 550i), I noticed the tail lights staying on after turning car off. After locking the car, the tail lights stayed on and then the 3rd Break Light came on and stayed on. All lights would turn off after restarting or just pushing the start button without foot on brake pedal. This happened every time I drove the car. I tried all headlight settings with the same results.


About the same time, I starting hearing a buzzing sound coming from fuse panel above battery in trunk.


A few days later, at night when I turned car off, headlights stayed on and went off and on many times like they had a short.


A few days ago, I could not get the lights to turn off, no matter how many times I restarted the car or just pushed the start button. I pulled the two 40 amp light fuses in the glove box fuse panel. The lights went off but the battery was drained overnight.


Yesterday, I pulled the spare tire out and found that there was a little water in the tray that the modules are in and a little water under the tray in the bottom of the trunk. I found that a seal at the bottom of the rear glass had dry rotted and was evidently leaking.


20200926_121408.jpg 20200926_123828.jpg




I pulled all of the modules and examined them. After opening the RDC module I discovered that water had been in the module and caused quite a bit of corrosion. (pics attached). I tried unplugging the RDC module and removing the 7.7 amp TPMS fuse.

20200926_135927.jpg 20200926_134713.jpg 20200926_150318.jpg


When ignition turned on, there was still the buzzing sound behind the fuse panel above the battery for 5+ seconds (video attached). I then disconnected all of the modules in the same area as the RDC module that could have water damage. There was still the buzzing sound behind the fuse panel above the battery for 5+ seconds.



Today, I attempted to start the car to get codes from my Carly for BMW app but it would not start and then would not even release the fob from the ignition, no lights on dash..... nothing. It appears to now have a complete electrical system failure.


I have searched the internet & YouTube with very little help.


Any help anyone here could provide would be GREATLY Appreciated!


Cheers!

[Gman6262]

This looks like it may be long and painful to sort out. If you're lucky, you've blown fuses on all affected circuits. If you're unlucky, the shorting may have caused heating and melting on unprotected circuits - connections, grounds - typically where the wire diameter changes or there are less than perfect connections. Dry everything out, be systematic, and do a thorough inspection before applying power again. When you do get to live testing - make sure to cut the power at any signs of buzzing or arcing. You're probably melting something. Pull all the connectors from the fuse panel and check for signs of arcing or heating. Check fusible links for damage - circuit diagrams will help you find them. Good luck.

[jawanza91]

I'm having this same issues and those same sounds. How did you fix it? I'm going to replace my power distribution module (that fuse carrier).

[Swfl3390]

Hi, I just read your thread and although I don’t think I have the water damage, I for sure have the same sound coming from the same place in my trunk. Did you ever get it fixed or find out what was wrong? Thanks

[jawanza91]

Hi, I just read your thread and although I don’t think I have the water damage, I for sure have the same sound coming from the same place in my trunk. Did you ever get it fixed or find out what was wrong? Thanks

I had the same issue and got it fixed with a CAS module repair via an eBay vendor. It was ~ $165 and fixed so many issues.

[Swfl3390]

I’ll try that, thanks!

[yovan.noel]

Did you figure out the root cause?

I’ve been trying to diagnose mine but not having much luck…

Hi and thanks for reading,


A few weeks ago (on my beloved 2008 E60 550i), I noticed the tail lights staying on after turning car off. After locking the car, the tail lights stayed on and then the 3rd Break Light came on and stayed on. All lights would turn off after restarting or just pushing the start button without foot on brake pedal. This happened every time I drove the car. I tried all headlight settings with the same results.


About the same time, I starting hearing a buzzing sound coming from fuse panel above battery in trunk.


A few days later, at night when I turned car off, headlights stayed on and went off and on many times like they had a short.


A few days ago, I could not get the lights to turn off, no matter how many times I restarted the car or just pushed the start button. I pulled the two 40 amp light fuses in the glove box fuse panel. The lights went off but the battery was drained overnight.


Yesterday, I pulled the spare tire out and found that there was a little water in the tray that the modules are in and a little water under the tray in the bottom of the trunk. I found that a seal at the bottom of the rear glass had dry rotted and was evidently leaking.


20200926_121408.jpg 20200926_123828.jpg




I pulled all of the modules and examined them. After opening the RDC module I discovered that water had been in the module and caused quite a bit of corrosion. (pics attached). I tried unplugging the RDC module and removing the 7.7 amp TPMS fuse.

20200926_135927.jpg 20200926_134713.jpg 20200926_150318.jpg


When ignition turned on, there was still the buzzing sound behind the fuse panel above the battery for 5+ seconds (video attached). I then disconnected all of the modules in the same area as the RDC module that could have water damage. There was still the buzzing sound behind the fuse panel above the battery for 5+ seconds.



Today, I attempted to start the car to get codes from my Carly for BMW app but it would not start and then would not even release the fob from the ignition, no lights on dash..... nothing. It appears to now have a complete electrical system failure.


I have searched the internet & YouTube with very little help.


Any help anyone here could provide would be GREATLY Appreciated!


Cheers!

[Selyan]

Any luck on this issue ? Having the exact same noise above the battery, I tried everything

[BudB]

Today, I attempted to start the car to get codes from my Carly for BMW app but it would not start and then would not even release the fob from the ignition, no lights on dash..... nothing. It appears to now have a complete electrical system failure.

I watched the video...OMG!
I was expecting to hear a slight buzz but that is a really major Buzzing / Electrical Arcing / Sparking sound.
The car is Screaming at you!
I wouldn't let it buzz for 5+ seconds if anything have someone put the key in just for a split second with your ear right next to the panel to try and pinpoint the Buzz
Do this really quick with your finger on the relay at Terminal 30 and see if the Relay is the Buzz..
Is the relay warm to the touch? It should be.
Watch this video
https://www.youtube.com/watch?v=vB3zusDVpAM

In the meantime Order the burnt RDC Module ASAP. (RDC Module 6782800-01) Plenty on ebay
What is the other module in the riveted case?
If the RDC Module is damaged then it's probably a good bet that water also got into the other module.

Realoem.com should help you with the part #
https://www.realoem.com/bmw/enUS/select

Except for a second to check that relay or have your ear next to the panel I would not put power to it again.
Obviously damage is occurring which has led to the cars Complete electrical Failure.

After your DIY is over and unless you are sure that you have found the issue..
If you can't.
Then it's time to bring in the Big Guns before any further damage occurs ..Get professional help!
Call your trusted BMW Mechanic (if you have one) if you don't then Tow your car to BMW.
It's nothing to be ashamed of.
I did it once paying my Dealerships it's $300.00 Diagnostic Fee.
In the end they had my car for almost a week and I never would have found the issue.
it was the best thing I could have done.
They quoted me over $2,000.00 to repair but instead with their troubleshooting results in hand I was able to fix my car for $175.00
Thank you BMW!
Saved my But!

As far as those Modules...
I'm active in a few Forums and at some point the thread always comes up talking about moving those modules from under the tire and up to the shelf on the left.
And every now and then a thread comes up from someone that didn't move them and got water in them.
And they get the bad news that none of it would have happened if they had just moved the modules from under the tire!
What a bad move BMW did designing that.
Or if they want then there protect them better and put a drain in the bottom so water has somewhere to go.
But that's beside the point.
In all of the water posts I've seen I none had any buzzing at the fuse panel like you.
So you are a first!
They just replaced the modules, code what they needed and move on.
Lucky You!
I feel your Pain!

Hopefully it will end well.
Good luck

[BudB]

If there was a way to get that video and burnt module in front of a BMW Technician
I would want to first see the look on their face and then hear what they have to say.
If your lucky you are not the first with this issue and they could give you the 411 as to what you've gotten into.
One of the worst modules that I've seen though..

Again, hope that it's nothing major.
Keep us updated.
Your results could help save someone else.

[jawanza91]

For anyone still reading 4 years later, getting a repaired CAS module solved this problem for me. I found a service that did CAS module repairs on eBay with great reviews and the owner had confidence this would be the solution after hearing my symptoms. It worked on my E60 550i.

[BudB]

So Jay550 you are jawanza91?
So glad to read that.
You kinda left us hanging.

Why didn't you complete the thread with the firther troubleshooting and solution?
That's one of the the point's of starting a thread is that in the end you pass on the Happy Results!
How are others to learn from your issues?
Then your thread lives on and can help many behind you!

Was the buzzing coming from the CAS Module?

[jawanza91]

So Jay550 you are jawanza91?
So glad to read that.
You kinda left us hanging.

Why didn't you complete the thread with the firther troubleshooting and solution?
That's one of the the point's of starting a thread is that in the end you pass on the Happy Results!
How are others to learn from your issues?
Then your thread lives on and can help many behind you!

Was the buzzing coming from the CAS Module?

No I'm a different person - posted my finding in 2021 if you scroll up. The CAS module is under the glove box IIRC. There was nothing wrong with the relay block in the video and nothing wrong in the area the sound is coming from. I also posted my results in the E60 Facebook page. I've moved on the from the E60 platform unfortunately. Good luck all and keep up the great DIY friendly atmosphere.

[BudB]

I would still like to know what the Buzzing / Arcing sound that Jay550 experienced in his trunk
I think that the CAS for my '06 530i is located under the steering wheel.
Glad you got it sorted out.

[Selyan]

Here is what I have done this far, I replaced all relays, replaced the battery, replaced the trunk fuse box, replaced the IBS cable, sent the CAS for testing and it came back as no issues,The trunk Module is fine with no signs of water or corrosion, I replaced the fuse box in the front by the DME. the only remaining item I can think off is the Alternator Power Management.