Noise While Braking in snowy roads

I get a Noise While Braking in snowy roads while driving around 50Kpmh. Is this usual ?
My dealer says that it is the Traction Controls System taking effect. But I have not switched on the TCS button on my panel. Does this come on automatically ?

Thanks

AS far as I know, the TCS kicks in on acceleration under slippery conditions and under 20 km/h. The noise it makes sounds more like electronics under the dashboard sending signals to the front wheel brakes. Unless I'm missing something, I don't see what the TCS would have to do with braking at 50 km/h... the ABS could kick in but it only makes the usual ABS noise of brakes coming on and off rapidly. So I haven't encountered the situation you're describing on my 03 Ody.