ABS and Brake lights on (no VSC)

Hello,

2007 prius 155 miles.
Yesterday noticed that after releasing parking brake, the red Brakes wont go off, and so as ABS and (!) light stays also on.
at first I thought it was stuck parking brakes, because they were generally barely stopping car.
tried few times brake release no luck.

After searching forums, I have found some similar threads, but none has solution.
So in my case, red Brakes, ABS and (!) is on. (no VSC). can and brakes work absolutely the same, VSC works.

tested 12V battery: at idle 11.5-11.8 on load ~11V with lights and etc goes lower than 11. so is it way bad? car doesnt have problems with starting.

second thing, can it be problems with rear calipers? I am going to replace it and hope no bleeding would be necessary.

what else should I check?

I see posts about paperclib diagnostic mode, but cant find any info which pinns to connect and where to read codes, if there is one, please link it

 

just an update:
battery goes as low as 10V and then car turns off. I will replace it now, see if it helps with ABS

 

thanks fro your reply,
yes, the battey does not hold a lights on for 5 minute,
just wondering if it needs recharging or replacing.

when ready, its steady 14.1-14.2, while driving also.

whats about calipers, i thought maybe they have worn enough for abs to think there is problem and self disabled.

 

just to replace calipers? the ATF system is not closed and ehrmetic?

yeap, I need it in any way I think.
it the techstream the soft toyota uses itself?