2009 Prius MFD intermittently working

Usually the display is going bad . I just get replacements from other cars.

 

I had an odd experience that was a little different than yours. It may or may not be helpful. Probably 2.5 years ago my MFD wouldn't come on when I'd start the car. It would take 2-5 mins of me driving for it to come on. I'd be listening to a podcast and get the tell tale 1 second drop in sound from the speakers as the MFD booted. After a while it just stopped turning on at any point on some drives. For the better part of the last year it might turn on mid-drive once a month. I looked up replacements and they were in the $1k-$2k range and put it off. About a month ago I found the Dr Prius app. I'd been using Torque pro without the extra Prius PIDs for years and ran across Dr Prius somewhere. When I was driving, most of the time I'd keep off the brakes. I figured the coasting did better regeneration than the brakes so I'd coast up to stop lights as long as I wasn't backing up traffic, only applying the brakes at the very end. I hadn't seen the SOC screen on my MFD for a long while since the screen stopped working. Watching the amps going into the battery and the SOC % showed me how wrong I was. Coasting netted me 17-20 amps and refilled the SOC % very slowly. Light to moderate braking over reasonable distance netted me 50-85 amps and really added to the SOC %. Dr Prius said I was initially in the high 40% SOC when I first connected it. I live in the Appalachian mountains so I took a quick drive over the mountain and back a few times, figured out how great braking worked refilling the SOC, and got it up to 77% SOC. Since then the MFD has come on every time I've started the car. I was absolutely baffled but apparently appropriate battery voltage is required to get something in it to work correctly.

 

The Toyota dealer won't repair it they'll replace it and it'll be about a thousand plus dollars if they even have it and their inventory 09 you're at the last of the series.