All warning popped up and battery drains.

Hi. I'm new member of th forum. I've been reading it before and now I need your help.
Recently I was working on my right side front brake pads. After I was done the "brake" and all the warnings popped up. I went to Autozone and tried to read the codes. No codes. One of you suggested to clear the memory with a pin which I did. After almost 300 miles they went off again.
What I also found - when I push the brakes, the monitor shows that Prius sucks the power from the battery as if it was moving.
My guess is - perhaps there's something wrong with a sensor and the computer kinda think that car is moving and lets the power from the battery to go to the wheels.
Since this is My first Prius and I don't know much about it, I might be mistaken. Please correct me if I'm wrong and how can I fix it on my own, if it is possible?
Thanks.

 

Sorry for the late answer. I'm kinda insanely busy these gew days.
No, there's no fluid leak.

 

O. Ok. So, there's no point of going to Autozone again. Can I buy such scanner? Do you know the cheapest and still good enough model of such scanner? You know, when you go to a dealership, they suck money out of your pocket by any chance.

 

I decided to work on the pads because there was weird sound every time I pushed the brakes. The sound was coming from the right side. I just took the caliper with the brake pads off and put it back. The noise disappeared for some time but the lights went off. Now I have both: the sound and the lights off. The monitor shows that the power goes from the battery to the wheels even when I stay at intersection.

 

Thanks for the response. I do push hard and nothing changes. That was my first thought. Can it be a problem with the brake actuator?

Thanks. I'll do it.