How did you install the BCM? Did you just disconnect battery and then switch it out? Or did you leave the key in accessory mode for a few minutes like in another thread?

 

To swap out the BCM, I disconnected the battery ground cable to ensure that there weren't any stray voltages and to allow the BCM to shut down completely. Then it's just a matter of pulling it up enough to remove the power connector and the cable assembly.
Pay close attention when sliding the replacement into place taking care that none of the wiring gets pinched or stressed.

 

It's also interesting to note that I was not able to resync my FOB to be recognized until after the BCM was replaced. It has some role in that process as well.

 

It would be interesting if you opened up the BCM and looked for any hot spots or burned out components inside (on both sides of the PCB). If you do open it up, could you please take a couple (or so) pictures and post here? Glad you got most of these fixed.


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Thanks for circling bad and telling us what resolved your issues. The common cause of high beam failure is the multifunction switch in the stearing column. Paul on YouTube has a video on how to fix that.

 

I sent my BCM (original one that failed) off to be repaired. Diagnostics say that the board is not repairable because the problem is a failed processor chip and the processor cannot be physically replaced. I don't know why the processor cannot be replaced, but that is their line of business so hopefully they know.
I have two options.
The first is to buy a blank BCM from the dealer and pay them to configure it. A very expensive option and most likely the dealer couldn't source a blank BCM and if they did, probably could not configure it.
The second option is to have the repair company take my working used BCM(well, it won't let me manually raise and lower the rear wing, control traction control or set for towing) and clone it to match my failed BCM. For $1,000.
They say that the BCMs are VIN locked to the car. I don't know whether that is true or not, but they would unlock the BCM before cloning it.

Well, that's the deal. I'm not planning to spend the $1,000 to clone a BCM. I can live without manually controlling the rear wing (it still goes up at 55 and back down under 40), turning off traction control and turning on the tow function.

If anyone knows of other less expensive options, I'm listening.

 

BCM cloned to a specific VIN?
I think that may be a load of Malarkey

My understanding is that they were plug and play, specific to model
ie
roadster or coupe
manual or automatic
and again for SRT (automatic only)
there should be 6 different BCM’s
(maybe base and SE are different)

When I cloned my NA as an SRT all I did was plug in the BCM for an SRT roadster. No oning to a different VIN I JUST PLUGGED IT IN.

I didn’t think there was any specific BCM programming that’s VIN related. Are you referring to the ECU? Those are VIN specific.

If you need a spare BCU you should be able to pick up one that’s specific to your model on eBay. For a LOT less than $1,000

Not sure of your specifics
ebay
automatic/ roadster $95.26

https://www.ebay.ca/itm/204646616116...mis&media=COPY

 

That is my understanding as well.

 

Thanks for your insight. I'm not going to pay the $1,000 to have my failed BCM cloned. The used one I got from eBay works....... mostly. It has the same hardware and software versions as my failed BCM and came from a manual roadster like mine.
I may gamble and get another used one just to see how it performs. I'm intrigued now.

 

Please let us all know the outcome.

 

I will definitely keep you updated.
I spent a little time in the electrical diagrams this morning to determine if the BCM cared in any way whether the transmission is a MT or an AT.
Apparently, the BCM is not involved or cares which transmission the car has.
So, if the above is true, you can use a BCM from an AT car in a MT car.
I'm going to buy another used BCM having the same Software level of 44/03 (44th week of 2003). The hardware build week is different from my original, but that really shouldn't matter. I think it's the Software level that is the most important.
The used BCM I am using now, matched all the build and level numbers, but still does not allow manual control of the rear wing, traction control or tow alarm disable. It does pop up the rear wing at speed as it should and then drop it down when it's time to.. Those missing functions could just be a result of the used BCM's age and gradually losing function.
I'll post an update after I receive and install the next used BCM.

 

I thought originally the replacement BCM solved your problems? Did the manual control of spoiler, traction control or tow alarm work with the original BCM?

It should be possible to find a replacement BCM that matches your original one either on eBay or at car-part.com Luckily used ones are not that expensive.

There must be other companies that can repair the BCM if you want to go that route. I am sure on the Mercedes forum there are more posts than on here.

You can try disconnecting the battery for 30 minutes. Then reconnect it and put the key in accessory mode right before it turns on and leave it like that for a minute or two to see if the replacement used BCM will sync with the car like I've seen in a previous post.

 

The replacement BCM resolved The most important issues (turn signals, wipers, door lock/unlock).
The manual spoiler control worked with the original BCM until it died. I cannot absolutely say that the manual switches for traction control and the tow alarm worked with the original BCM. I don't believe that I ever used those switches.
I found on eBay another BCM with the same hardware version and software version. I have ordered it and will post the results.
If I can have working lights, wipers, rear defroster, turn signals, rear spoiler(manual and speed deploy) locking/unlocking doors (manual and remotely) I can be happy.

 

Keep in mind that BCMs from SRT6s were never intended to operate the wing. There is some chance that a non-working wing when using a replacement BCM is because the replacement BCM came from an SRT6. I have no clue what the differences in software in the BCM (or even hardware) might exist between N/A and SRTs. I know one thing, the Germans did NOTHING the simple way with these cars.

Im interested in hearing what you find with your swapping and trading BCMs. Again, Iv'e been here since 2009. Only in the last year or two have we had BCMs dying. We are in unknown territory here, but with enough people experimenting and posting their results, we will learn........

 

I received the second used BCM today and installed it. I now have all known to me functions controlled by the BCM except manual control of the rear wing. The wing goes up on its own at the speed that it should and retracts at the speed that it should. It just doesn't respond to the console switch. The console wing switch worked with the original BCM, but I truly haven't used it in over 8 months so it's possible that the switch has failed or a connector is loose. I will be hitting the schematics to check out the differences between manual control and automatic control.
Either way, I can live without manual control of the wing.
So, for now I'll just drive the Crossfire and enjoy it.

 

Thanks for the update. I'm glad it worked.

 

So what have we learned from this thread?

Well, from this and some of the reports on Fakebook, I've learned that we've moved into a new era: The era where the list of common failures now includes BCM failure.

Our cars tend to 'eat' modules. The RCM and Pulse modules are simply boards with relays - easily fixed. But ECUs, PTCMs, CLP-SSMs, BCMs, SRS Modules, Brake Controllers - are all microprocessor-based modules that are nearly impossible to fix, certainly not by us average guys. To that end, I would urge all to take the generic "electronic technician suggested" methods of protecting sensitive electronics:

Avoid areas where EMPs are common (so stay away from nuclear bomb tests).
DO NOT put the top up or down without the engine running.
DO NOT run the car with an old battery (over 48 months).
DO NOT jump start - use a booster battery.
Add James' redundant grounding mod. GO here: https://www.crossfireforum.org/forum...le-engine.html
Keep battery terminals and clamps tight and clean.
DO NOT use a high current charger on the battery unless you disconnect the battery from the car.

I hope we can keep these cars going...................

 

Great advice and don't try to jumpstart other cars with your crossfire.

 

pizzaguy is right! It's those dammed nuclear bomb tests again! they mess up everything!
It even turns innocent lizards into city trashing giants. I'm tired of it!