Reading through the brake sections of the 2010 Prius Repair Manual, one of the first steps in any procedure seems to be "disable brake control". Searching the manual for that expression I found an instruction that includes hooking up "Techstream" and changing some software settings. FWIW, the Toyota Manual is pretty terse: all of the brake related procedures seem to assume you want to tear down the brake completely. They always say to remove the brake line and drain fluid. For a simple inspection and/or replacement of brake pads it's typically not necessary to open up the fluid lines. Anyway, just wondering, has anyone been doing brake checks, just the basic stuff like pad inspection and disk runout/thickness check, without getting into trouble due to not doing the "disable brake control"? I suspect the need to disable brake control only comes into play if you open the fluid lines, but not sure. Maybe also a problem if you were to push a piston back during pad replacement? As I said, the manual is really terse, just outlining a complete tear-down of the brake.
I read the same, as far as I can make out, you don't need to do this unless the pedal, the pedal stroke sensor or the ABS system are disturbed. The Prius readies the brakes for action automatically if you open the drivers door or touch the brake pedal and to prevent this happening you can disconnect the 12v battery. The Workshop manual mentions that a fault code may occur if you push back a calliper piston, I think it's to do with the pedal having to travel further to push it back out, but states that it is not a fault so the code can be cleared. You may have to take it to a shop to have the code cleared, although on many cars fault codes clear themselves (providing there is no fault) after a set number of start-ups.
