UPDATED: waited ten minutes with 12v disconnected and that worked. Note that the triangle came right back but by then the car was started. I’ll leave this post up in the small chance that it might help someone in the future (maybe even me)… Daily driver (no glaring issues with this one) but I had seen the red triangle yesterday while driving (code said hv issue) and made the note to look further into it. Today I’m on my way to autozone and made quick stop. Upon returning to car, I get triangle and no ready. Normally think clearing the triangle would allow me to at least get the Ready so as to get home… but I absentmindedly left my scanner in one of the other cars. At this point, stuck and need to find a way to get to Ready. Unplugged -reconnected positive terminal, pressed start twice, held down start, … Wonder what are some other hacks to try. This is a gen2 other than the one posted earlier this week (where the key was not recognized)
Maybe try the safety plug on the hv? It’s pouring rain. Might not be safe but that might reset whatever the fault is/was. Either that or walk home… or continue to google and wait for the Priuschat gurus that have been saviors in the last…
Sounds like you may have an HV fault isolation fault so on and so forth usually a cheap scanner clear the code twice get you started again and running ready ETc. bit won't stay that way .
^ This worked (as you saw) to get the ECU to forget it knew about the fault. ^ Not this. Unhooking the 12-volt battery worked, because the ECU memory is maintained on 12-volt power. The safety plug interrupts the high-voltage system, which is separate. ECU memories do not get their power from that. You didn't reset anything that the fault is/was. An ECU noticed that a fault exists, and you cleared the ECU memory of having noticed that fault. That was enough to let you start the car again, but the real thing you have to do is find and fix the fault. Isolation faults somewhere in the hybrid system, as Tombukt2 pointed out, are programmed with the kind of fail-safe behavior you're seeing: they don't shut the car down if detected while operating, but they do prevent going READY next time. So we could probably guess that, when you read the trouble codes, one will be P0AA6. Still, reading the actual codes beats guessing. And if you do have P0AA6, the 3-digit INF code that goes with it will help you narrow down where to look for the fault.
