P0A93 and P010A codes

2005 Prius 189K

On Friday, my son (#1) was driving my only car, the 2005 Prius, up north for the weekend. It was very hot and humid for Wisconsin around 105 degree heat index. About 12 miles out of town, several things starting happening:
- Multiple warnings lights came on (check engine, master warning, brake & ABS)
- Constant beeping
- Brakes seemed to require more pressure. He thought maybe it was braking more on one side.
- AC fan pressure seemed to decrease
- Once the car switched automatically to neutral
He stopped the car and called myself and my other son (#2).

Son #2 went to help him and swapped vehicles with him. Son #1 continued up north (in a vehicle that gets 12 MPG). Son #2 looked over several things (coolant level, and others). Son #2 drove the car slowly about 6 miles to a place off the highway and left it there on a side street.

I had purchased an OBD2 reader last fall, but had never used it. On Saturday, I biked to the car and plugged in the reader. At this time the brake warning lights were off, but the check engine & master warning lights were still on. I tried two different apps. The first app reported P0A93. I drove the car to other side of the road to get in the shade. The second app reported reported codes P0A93 and P010A. After the using the second app, the warning lights on the dash went away. I didn't do anything on purpose to clear the warning lights (not sure I could do that, but I've never used OBD before). I drove the car about a block and everything seemed fine so I drove it home slowly, going on side streets.

Today (Sunday) I ran the OBD2 reader again and the codes P0A93 and P010A are still being reported. There are no warning lights on the dash. I've never had any problems like this in the past. The 12V battery was replaced about 15 months ago.

I should note that for the last year, the speedometer part of the dash will go out sometimes, but will eventually come back on. When I turned the car on today (Sun), I did see the check engine light come on briefly and then go out, so I believe the warning lights part of the dash is still functioning even though the speedometer part is not.

So the questions:
1: Could some or all of the problems be related to the extreme heat on Friday?
2: From what I found online the codes mean:
P0A93 - High voltage system may overheat is defined as a Inverter "A" Cooling System Performance
P010A - Mass or Volume Air Flow "B" Circuit Malfunction
What does that mean translated to a non-technical person?
3: Does the presence of the codes now indicate a current problem or a past problem?
4: What should next steps be?

Thanks much for any suggestions.

 

Thank you very much for the response!

1. I see the inverter pumps vary greatly in cost from Amazon. Is there a reliable replacement pump or would you recommend going with genuine Toyota?
2. When I replace it, do I need to clear the fault codes or will they clear automatically?
3. Since there are no visible warning lights and the car seemed to be ok driving the few miles back to the house, is it ok to drive the car minimally until the replacement part arrives?

 

Thanks everyone for your help.