So here is the deal-- Burning smell most pronounced when driving uphill. Bad electronic burning smell. Took hybrid battery all apart to inspect everything and everything looked good (no burnt electrical connections). Put it back together but removed the rubber vent tubes (some people said that might be causing it and that they don't do anything. Drove for a couple more weeks and now started to smell burning smell again. Got a check engine code today. Car still drives good with good power but the check engine code makes it so it won't go into drive only neutral unless I clear the code. Codes I got: (see photo). Took hybrid battery apart again and noticed a fried connection at one of the power relays. Do you guys think just replacing the power relay might fix my problems? Or do I have bigger fish to fry?
Wow did you take this apart before and didn't tighten the part down? Loose electrical connections can cause fires. I have a spare part with all the electronics (minus the ECU). $50. Hopefully that can solve your problem.
I made this mistake once... Was juggling three different battery packs with two different cars while explaining Prius to person I was doing repair work for and forgot to tighten the bolt down, which popped off on the drive home. Soon as you swap out that bad relay, you should be ok. And maybe the relay was what went bad, not your lack of a tight connection?