Prius c 2015 c1256&c1391 code

Was pulling out of car park when I noticed abs,traction control, brake light n warning light came up, it went off but came back up as I was driving that when I felt the difference in the brakes it sank more n felt like I was loosing pressure until the pedal bottom out, the brake assembly made more noise than usual, the pulse I felt when I started the vehicle from the brake pedal it not present once the lights or on but when off I feel it,note before I bought this the brake assembly was replaced with a used on could it failed already or could it be the master cylinder need changing or entire assembly again

 

No it’s dead had to get a jump when my brother came to assist when the brake started acting wierd drove to work today tested battery it’s dead, but prior to that my brother said he had to change the abs brake actuator pump cause he had the same issue n his mechanic told him to change it but also recommended he change the brake booster assembly but he didn’t so now with the same issue, the code that I got when i scanned suggested it was booster assembly at fault, would a dead 12v battery cause those issue?

 

Fuel level is full, pumps run constant n only take a 5sec interval, if foots on pedal it constant. If the abs,traction control n brake light comes off dash regularly braking resume but as soon as light appears u feel u start to lose pressure in braking until it hits the floor n secondary braking system chips in but I have to sink pedal hard for that to happen.