Can't go into ready.

welcome!
unless someone knows, you will probably have to have the trouble codes read

 

You might have a problem from the hybrid battery area.
Read codes out first, and post them here.

 

1) Ensure the battery cables are tight at both posts and the negative body ground.
2) There are codes stored. Your coded reader or the store/shop you are using, does NOT have equipment that can read ALL of the Prius codes.
3) Consider contacting member "TampaPrius.com" (Todd) for help.
4) READ the owners manual to understand what the warning lights mean.

There is only a parking brake is activated warning light: "BRAKE".
There is a brake system warning light. The car is telling you that it has detected a problem with the brake system, that you are ignoring at your peril. You are mischaracterizing this as "round brake drum light," which does NOT exist.
VSC = Issue with traction control which is likely related to the brake system warning light.​

 

If you DIY, you should get "mini VCI w/ Techstream" ($25+ at Amazon). Even if you don't DIY, it is a useful tool that will save you the pricey Toyota diagnostic fee of $100+. Techstream is the official diagnostic and maintenance software written for Toyota/Lexus and used at the Toyota/Lexus dealerships.

Does NOT matter who you buy from, as there is likely only one or two producers of the knock off cables and software from Panda land. Be prepared for returns b/c their is NO quality control for these knock offs. People have reported the need to order a second cable, since the first cable did not work.

The hacked copy of Techstream works easiest on a Windows 32bit OS laptop. Ask friends/family in IT if they have an obsolete laptop (XP, Vista, 7) laying around. They can probably give this to you free of charge. Use this laptop only for Toyota/Lexus diagnostic purposes ONLY. NO email, banking, bill payment, etc, since the software is hacked. MAC install possible, just search.

 

When the OP gets the codes read properly he will have a P0AA6 code. That's a high voltage isolation fault. It's the only fault condition that allows the Prius to run fine until shut off and then not go ready.

 

Right, P0AA6 wouldn't show up as a problem with the modules. It is a problem with insulation.

 

It would be interesting to know what tests the "Hybrid Specialty Shop" performed. They should have been able to pinpoint the source since your leak is at the point of quickly returning after being cleared.

One test uses Techstream and it's sub or info codes to simply tell you the area of the leak. Sometimes there are not any sub codes that identify the leaks source.

Here's another test that does not require any special tools or codes readers. It will only work if the fault reappears quickly after being cleared.

Here's another video showing how to test the cells for leaks. This guy has awful safety practices. Wear gloves and use an alligator clip for one of the test leads so the test can be done one handed.

 

well done!