CV 34/35 may be setup using either MM or DCC mode

As you have a MS2, the DCC option is a bit cleaner but it involves temporarily ..
- setting DCC on the m83 (DIP switch 10 on)
- setting the MS2 Accessory protocol to DCC

Then you (temporarily) define a DCC Locomotive, as this is used to send the programming stuff to the track. (address is irrelevant)

Note:
- make sure your m83 is the only thing connected to the MS2 in the following
- ideally you would have an external power supply for the m83 - but this is not essential for this little job

From the Loco edit screen (Shift-Loco)
- scroll down once to select programming
- scroll (Shift-dial) to address 34
- read
- change to the value you wish (1=3Way turnout, 2=Doubleslip)
- write

- scroll (Shift-dial) to address 35
- read
- change to the value you wish (1=3Way turnout, 2=Doubleslip)
- write

- Exit out to main menu

Revert
- MS2 Accessory Protocol to MM
- Set m83 DIP 10 to off (Power Off, change switch, power on)

Test


if you do want to persevere with MM mode, please refer
http://www.maerklin.de/f...mmierung_M84_Signale.pdf
This is designed around the 6021 but can be implemented with the MS in a (even more) convoluted way.