Well, I can’t explain why your vehicle will drain the battery in a couple of days with the parking brake set. I did parasitic drain tests on my vehicle with the parking brake set and with it off and saw no apparent difference.
I haven’t actually caught my screen not shutting down, I can only suspect that for some reason, it didn’t one time. Yes, I too was told I wasn’t driving the vehicle enough. I called BS on that as others have had the issue with daily drivers, and just went out the next morning to start it and the battery was flat. Both hybrid and gas models.
I did notice that there was a software update done on my 2020 at the 5,000 mile check, that doesn’t seem to have been recorded anywhere. I also noted that the gas tank and sender were replaced, but nothing appears in the record on that either. Not in the service record online, that’s for sure.
Getting back to your problem, it’s possible there could be some current drain through the limit switch/proximity device that tells the actuator the parking brake is set. Not sure what they might us, but there has to be som kind of sensor to remove power to the unit. If you can pin. It down to the parking brake, which it appears you have, you might be well ahead to just demand that they replace the parking brake actuator, and see if the issue goes away.
In these vehicles, there is so much magic stuff that I can see how a dealer with only a limited amount of time to troubleshoot, could easily miss something. My car did something very weird last night: The eco AC system usually only supples AC to the driver if there is one person in the vehicle. Last night on a trip out, it was supplying air to passenger and. rear. Then, on the way home, it operated normally and only supplied it to the driver position. Go figure. It was cold though, 41f so I wonder if the system is smart enough that it knows it needs to supply heat or air all around the vehicle until it heats up enough for the one system to be able to maintain heat.
Yeah after a couple of go-arounds with this it seems the issue is related to the communication module that's built into the vehicle. From my understanding, the module attempts to connect back to Toyota but fails to communicate and gets stuck in an endless loop which causes the battery to drain. So the service bulletin related to a firmware update released by Toyota addresses this specific issue. I was able to confirm the software version by going into the service menu:I had it happen to me yesterday at 6AM except mine was totally dead, but I did not charge it. I had it towed to the dealership under warranty. The service manager just called me to say it's ready to go. I asked him if he knew why it died. Evidently there all the underlying systems kept running even after I turned the car off. He said they had to do a "one-time update" to it and I should be good to go. I've never heard of anything like that ... but my former vehicle was a 2004 Chevy Silverado which was 0% electronic.
1. Key in the ignition to "On", but don't start the engine.
2. Power / Volume to "Off"
3. Menu --> Display --> Screen off
4. "Seek" (press 5 times) *
5. "Track" (press 5 times) *
I ended up getting the free firmware update complete as well and have not had any issues since.