2008 - Not Starting, No Lights

I would suggest something does not add up. After shorting the battery posts with a wrench was there a failed jump start attempt? A reversed polarity jump start would blow fuses or fusible links at minimum.

I can understand the 12v battery failing from the direct short but not the inverter. It's more likely other fuses or fusible links are blown.

I would probably check all fuses one by one ensuring they are all good and none are in the wrong slot. Most likely I would reinstall the original inverter as well.

 

The thing with that is, the car has two things in it that are technically big DC/DC converters. One of them converts the traction-battery-level 200ish VDC down to 12 VDC for the electronics and aux battery charging. The other one converts the traction-battery-level 200ish VDC up to 500ish VDC for the motor-generators. (That one is also bidirectional, and can buck 500ish VDC from the MGs down to 200ish VDC for the traction battery.)

Most often, Toyota uses different names for them. The 200-to-12 one they call the "DC/DC converter", and the 200-to-500 one they call the "boost converter" (even though that one can both boost and buck). The different names mostly ward off confusion.

It's different in the fortune cookies for trouble codes though. P0A08 and P0A09 are both about the 200-to-12 one (the one Toyota calls "DC/DC converter"), while P0A94 is about the 200-to-500 one (which Toyota calls "boost converter" instead, but SAE International still calls a DC/DC converter, 'cause that's what it is).

Because those are all P0 codes and SAE is in charge of defining P0 codes, those all have "DC/DC converter" in their fortune cookies, even though they are about two different parts.

For the purposes of this thread, with P0A08 / P0A09, those codes are about the 200-to-12 one that supplies the car electronics and charges the 12-volt battery.