Bachmann Heavy Mountain internal decoder CVs ?

Hi to all and sorry for cross posting this, but really seams it was a “nation security” matter find some info about!
Have somebody knowledge of what kind (brand?) of decoder is factory installed on this N scale steam? On the paper included with the loco was only mentioned two functions (light dimming F10 and light On/Off F1). I “presume” the address is on the usual CV, but have not found any description of all CVs, also Googling around: Any idea where to search?
My problem is that I want to add a Digitraxx SFX 0416 (sound only) decoder to this engine (having two decoder sharing same address) and knowing more on the original motor CVs option will be useful.
If I remember well on Digitraxx decoder there is a bit to “freeze” or “block” the decoder for this purpose?
Thanks in advance for any suggestion.
Cheers
Enzo Fortuna

Hi Enzo

Have you emailed Bachmann or searched thier web site? The address CVs are short addyCV1 long CV17 +CV18 No matter which decoder it is. NMRA CVs are standard but some decoders do not use all of them. If your DCC system can read CVs look at CV7 and it will give you the manufacture code then go to the NMRA web site to cross the code with a Manufacture.

Pete

Bachmann “DCC On Board” locomotives use a custom Lenz decoder with very limited CV adjustment capabilities. Other than the address, I don’t think there’s much that can be changed.