I have the new Märklin 051 lok (37814) that comes from factory with a buffer capacitor. I'd like to swap out the factory decoder for an ESU LokSound5 decoder. I just don't like the way Märklin does their steam sounds. Does anyone know if I will be able to program the CV's needed for the buffer capacitor into the ESU decoder?

I compared the buffer capacitor CV's of the lok to the CV table of the stand-alone buffer capacitor 60974 and not all of the CV's are listed on the lok (at least from reading the lok on the CS3). Does anyone have any insight to this?

Here is the lok in question:

I have several loks with ESU decoders and ESU buffer capacitors so I'm familiar with them. I'm not familiar with the new Märklin buffer capacitors built-in to the loks from the factory. Is there a way to bypass them without de-soldering them from the Märklin decoder adapter board?

I guess Märklin forgot to add this detail on their website as well as in the instruction manual included with the lok. I can assure you, this lok definitely has not only one, but two buffer capacitors in it. Buffer 1 is for sound and motor and buffer 2 is for lights and AUX outputs. When I cut power to the track, the lok keeps running for a second or two and the sound continues.

Plus, you can see in the lok's setup menu on the CS3 that the capacitor is labeled as an "electronic flywheel":





I don't know why Märklin didn't announce that this lok has a buffer capacitor...

You're correct about the lok only having one capacitor:




I thought it may have been the same setup as the 60974 add on capacitor from Märklin:

Well, I sent an email to Märklin Digital asking about this and the reply I got was- "Hello Derek, there is no way for us to know what would happen with a third-party decoder. We don't test for this since the locomotive is supplied with a working decoder."

I also had a lengthy discussion on the ESU German forum about this issue. As of right now, there is no way for an ESU decoder to control the Märklin buffer capacitor. However, I might be able to swap to an ESU decoder and just disable the Märklin buffer capacitor; then just use an ESU PowerPack capacitor. As much as I don't like the steam sounds Märklin produce, I don't think I am going to install an ESU decoder and PowerPack right now (might wait until the warranty runs out).

I listened to some of the sound files available for the mSD3 decoders and wasn't impressed either.

Guess I just have to live with sub-par steam lok sounds coming out of my BR051 for a while.