Did you have the brake squeal sound working before? (ie is there some recent change in software/settings/upgrade applied that caused what was working to now no longer work)?

I ask because on Märklin locomotives, it appears that the brake squeal sound is produced entirely by the controller logic on on the locomotive decoder, and it is triggered (if not disabled by the function to disable squeak) - IF and ONLY IF the trains actual velocity is above its controller set velocity (and the velocity is above 50 possibly) and the ABV causes the speed to reduce gradually to the desired speed the controller set (zero) - so one manually operating the loco at a high speed above 50, then turns the desired speed down to 0.

When software like TrainController does the speed regulating to slow the train by setting speed steps gradually slower, that prevents the Märklin decoder from triggering its internal 'brake squeal' feature. There isn't a way to get Märklin controllers to generate brake squeal by function or programmatically.

So if it was working and now its not working, some setting may have changed such as ABV is turned off?

(I'm basing this off of other discussion threads on the break squeal issue when using Märklin decoders):
https://www.marklin-user...40339-Brake-squeal-noise

From what I understand, there isn't a function to test the brake mode. There is only the act of rapidly slowing by requesting a speed of 0, while the loco is in motion, with ABV on, and the settings that relate to brake squeal duration/levels being set in CVs possibly. There is a minimum speed to even generate a squeal as well (50 is what i read somewhere) - so if the requested speed is 0 and the actual speed is > 0 and the speed is/was > 50, and it meets the other CV set criteria - only then will he decoder generate the brake squeal sound.

IE there are a LOT of ways to prevent the brake squeal sound, and no way to force it to play. Its a "Märklin feature(tm)"

If you find a solution, do let us know.

After reading about this in an earlier thread I also noticed that Brake Squeal has disappeared all of a sudden, also on version 4.2.1 .

I've increased The braking Delay, played around with Vmax and Vmin, nothing brings it back.

I have found the problem.

1. It is not possible to use the Brake Squeal by using the Test button on the configuration page. No matter what I do it will not work.
However.
2. Make sure the locomotive sound (diesel/steam) is switched ON. Then the brake sound does work when slowing to 0 from a good speed. If the locomotive sound is not switched on as well, the brake sound does not work.

I've test run a few other M loco's (mfx mainly) and they are all the same.

I seem to remember this being the case although it had escaped me on this occasion.

Hi!
We have many threads about this "issue".

The name of the function is "Sound effect: Squealing brakes off" and it does what it advertises: it prevents the sound of squealing brakes when it is activated.

Only few Märklin locos have a function "Squealing brakes" where you hear a sound when you press the "Test" button.

Did I just read that to hear the brakes squeal you have to have the squealing brakes in the Off position. Don't understand that.