(I will take this to the dealer, but I don’t trust them much as they misdiagnosed my last Prius for something that was actually their own fault.So I just want to see if this is a known issue anyone can give advice on.) 

2017 Prius with 245K miles. Traction battery health is getting low, but still performs decently. Aside from this malfunction that keeps cropping up every couple months or so. Dr Prius will never give me a code for it. Last “Toyota specialist” I took it to (November) said the code was related to the throttle pedal and I let them replace that, even though I doubted it was the actual problem. I’m kicking myself that I didn’t ask for the code. 

I’m guessing it’s something electrical since this tends to happen when I have some combination of lights and music and A/C or heater on high or phone charging. It first comes on with “Reduced output power” like in the first picture, switching with the pre-collision message. Acceleration is limited for a least a few seconds. It either corrects itself after that or else I have to pull over and restart it. Then the messages will continue switching, but without the “reduced power” as seen in the third pic. The car seems to work perfectly fine at that point, and the messages will go away by themselves after a few restarts. 

Last night was the first time it’s happened since November so I was hoping the pedal swap did somehow fix it. But no such luck. 

Are there specific things I should ask the dealer to check since chances are the messages will go away (and the code with it) before I can get it to them?

Malfunction that comes and goes?