2002 Gen I with P3125 code.

My 2002 Prius died the other day.

Getting DTC P3125 when I ran it through my scanner, but I don't have an advanced enough one to get the sub-codes.

It's got 215,000 Miles on it, so I would expect something major to be happening at this point.

Here's a detailed description of what happened --- I was driving down the freeway the other day and started noticing my car was sputtering a little bit and losing a slight amount of power. I pulled over to a restaurant to say hi to a friend; when I came back out I started the car and the check engine and battery lights came on. Hmm... About 10 more miles down the freeway the car started heavily limping and barely was able to get me off the freeway, then the car completely died. When I would start it back up it would die in about 5 to 10 seconds. The 12v auxiliary battery, not the main hybrid battery, had completely died.

I figured it might have been just a dead old battery that needed replacement so I put in another new one. It ran amazingly for about five minutes around the parking lot, then the same thing happened again. It completely died just like before.

The 12v battery isn't getting re-supplied with the juice it needs. Something's wrong in there.

The either the inverter is shot, it's just overheating due to a faulty coolant pump, or the MG2 generator isn't putting juice back into the 12v system.

I checked the fluid reservoir. It looks like it's flowing, but there is a few bubbles floating to the top of the fluid. Is that normal?

Anybody solved this problem before or know of a good hybrid mechanic in Southern California who could help me?