New to forum -- ABS lights and brakes

The lights on the dash are minimal information; they only mean the computer controlling the brakes has trouble codes it needs to give you, indicating what problems it is aware of.

The dealer should have given you the codes. The local guy should have given you the codes. You should have given us the codes. If you don't have the codes yet, they should be got.

There are scan tools available that plug into the diagnostic port under the dash and can retrieve the codes (and more detailed subcodes, and other information to go with them). If you don't have access to such a tool, there is a more primitive method where you can use a short wire between two pins on that connector, and count light blinks on the dash to get the codes. (Many threads here on PriusChat have the details.) You don't get the subcodes or other information that way, but you do get the basics. Not all computers in the car can blink codes for you that way, but the brake computer definitely can.

There is nothing weird that it "works fine" when reset. The point of having a computer detect warning conditions is for it to be able to tell you about them while they are still warnings. When it detects the problem, it goes into a protective fail-safe mode (which is the change you notice in how the brakes feel). When you reset it, of course it will not be in the fail-safe mode anymore, until the next time it detects the problem and reissues the warning.

 

If your mechanic just reset codes and did not change the brake pump and master cylinder yet, that is your next move. Especially since the dealer already diagnosed the problem. The dealer will change the brake pump and master cylinder with new parts. Verify what the second guy will do as some install used parts. There are no rebuilt parts available. Either way it is a labor intensive job. If you go used be sure to get a year or more parts and labor warranty. Negotiate pricing with either shop.

Often the brake pump has to run excessively for a period of time before setting codes. It may still work but there is most likely nitrogen / air in the lines which is part of the failure mode. When it does fail completely there is a failsafe with no power assist and dramatically increased stopping distance. Don't wait for that day.