Gonna replace brake fluid using the "Invalid mode" approach, have some battery/key fob questions

Do you have reason to believe there's something wrong with your brake fluid? Is it black brownrun a test strip in it to make sure. It's still valid or okay similar to what you do for coolant I mean I've got generation 2 Prius that have brake fluid that's been in there since well probably the car was sold as long as it doesn't eat the seals and turn the reservoir black looks like the same as it went in when I bought the car brand new or whatever the case may be and it seems to test and work well I'm not dumping it for what exactly what's the net gain.? If you live in a rust area where brake lines get rusted out like Pennsylvania places you can change the brake fluid all you want You better be looking at your brake lines under the car because as soon as they start taking on air and leaking the game is pretty much over and if you're in a nice place like the southeast United States where I live from 2005 on up to at least 2013 those cars will probably go to the junkyard with the original brake fluid in them because it lasts that long and it's become something that you really don't need to fool with that much it's a hydraulic system that's pretty solid and works quite well but no there are no serious pitfalls than a generation too I'll run the brake fluid out of the reservoir from the farthest wheel cylinder in the back until it gets almost to the last drop of fluid going into the tube feeding everything in that system and then spill it up with fresh but it run two or three minutes out of that rear furthest line then go do the one on the other side and then the left front and then the right front all by just gravity I have nothing but time I don't need to suck on anything and make it happen quicker I got other cars to work on well that's just dripping into a container move it over to the other wheel after I close that wheel off and open that one and let it drip 10-15 minutes from the front of the car to that container in the back through that little 1/8 line 5 to 8 minutes should clear it and have the fresh fluid all the way in that line onto the next. And it worked I've had no problems doing this is how I used to do older cars when I'm by myself and don't want to use a bunch of tools sucking and blowing and all of that.

 

It’s ok, doesn’t matter.

When getting the car into Invalid mode, it’s imperative to have parking brake set. Have the car “on” (two pushes of start button without foot on brake).

also, be careful not to rotate a wheel; it’ll apparently kick you out of the mode. I’ve not tested this.

I just used clear tubing, no mechanical suction. I did have a proper bleed screw coupler, makes connection more secure.

Only exception I noticed, he didn’t follow Repair Manual sequence, which says to start with front/right, then go around counter clockwise. Not sure if it mattered, but I did repair manual order.

A smart charger would be best, something that actively tops up the battery.