My car has twice had the master warning light come on, and I was able to drive it to my mechanic the second time where he pulled the error code P0A08. Incidentally it has NOT occurred since then, but if there is a DC/DC converter issue going on, would this affect gas mileage in any way? (Not a car person, so don't really even know what the converter does).
DC/DC converter problems are so rare they're practically non-existent... Maybe you mean P0A80 ? That's a common error code when a battery pack gets old. Best thing you can do at this stage is buy an inexpensive OBD2 reader. Here's buyer's guide: Hybrid battery diagnostic and repair tool for Toyota and Lexus Then use Dr. Prius app on your phone to take screenshots of your battery packs vital signs and clear the erro codes as they come up and they we can go over all the options for repair based on what your budget allows.
I hope the OP will chime back in if the P0A08 was a typo for P0A80. P0A08 is also a perfectly cromulent code. The converter is what supplies the car's 12 volt electronics while you are driving, and keeps the 12 volt battery charged. If the code really was P0A08, it means the converter detected a problem and switched off, and the 12 volt battery, not being charged, went below 11 volts. If that's allowed to continue, it eventually will have a severe impact on gas mileage, in that no matter how much gas you have, you won't go anywhere.
I mean, I wrote down what the guy told me, which was P0A08. Thanks for clarification on what the code means. Can I just let this go unless the warning comes on again, or does this need to be addressed? I haaate how old cars suck money, but I just replaced the hybrid battery in this one so it's not going anywhere for a while.