Technical Speed dial jumping and Brake control warning

[gergo452]

I have recently bought a 2016 Fiat Tipo Hatchback T-Jet 1.4 car. This morning three errors came out simultaneously, which I think are connected to each other. The spedometer dial starts constantly jumping down and up (jumps about 20km/h), but the digital speedometer shows the correct speed. Besides this two error warnigs appear at the same time: "Chech Brake Control" and "Park Assist Unavaiable". I have met with this error a couple of weeks ago, but after a restart it didn't came out until now.
Has anyone met with this kind of error?
There is a short video about the issue:

 

[RichardH13]

This may sound strange, but it could be the battery, especially if its the original one.

Weird things happen when it starts to go, cold weather doesn't help.

I doesn't take much of a voltage drop off to cause it