Tried to jump using the remote positive terminal under the hood, no dice. Shouldn't this have given the 12v battery enough to get me going? Going to try again with a different set of cables just to be sure. Any thoughts?
It should have worked assuming you hooked up a good ground also. Leave it on for a few minutes or put a charger on it for a while. If you measure the 12v voltage with a meter or use the mfd and the voltage is over 12vdc but you still can't get ready (and/or if it momentary flashes to ready), you could be experiencing inverter failure. Only way to know for sure is to read the codes. If you can't get it going have it towed to a dealer. If it is the inverter Toyota has announced a 10 year unlimited mileage warranty on the part.
Did you have last year's inverter firmware flash recall done? I would try to jump at the 12V battery terminals under the rear passenger side cargo area cover.
I didn't get the flash recall done... Jumping the battery directly after manually popping the hatch did the trick. I must not be using the remote terminal right; couldn't get a voltage read across it (used engine block as ground). Thoughts?
Thanks for that info, good to know if that ends up failing. The security guard at my complex says that a light was left on while I was away for the week, so hopefully this was a one off and I can squeeze more life from my battery. Thanks all!
For most cars this will be great as they use an alternator attached to the engine, so use large ground straps between the engine and the frame. The Prius has no alternator, so needs no real ground strap. This limits its use as ground, I would use a frame bolt, myself.
Any bare, substantial metal on the engine or body will work as a ground. Strange that the jumpstart terminal is not working, wonder if it's connected to the low battery problem. What sort of voltage are you reading, when measured at the battery?
Doing that may get you a "Check Hybrid System" message though, for an unexpected ground detected at the inverter. It will go away after several good starts, but given the circumstances of needing a jump start, the message may freak out the owner. Using a frame bolt is just as effective, and less prone to give an erroneous error message.
The jump terminal has a conductor on only one side though. I wonder if the OP used a jumper cable that only has one conductive jaw, maybe one metallic jaw, or two plastic jaws with a metallic insert in only one side?
You need to get the inverter flash recall done or it could invalidate a subsequent inverter claim. I use one of the engine compartment bolts for a jump ground as specified in the manual. You should have someone show you where for next time.
I use this. It might be a bit fiddly for larger clamps, but readily accessible, and close by the jumpstart terminal. It's funny, the day we took our first test drive in the car, it had a dead battery, and this what the mechanic used to jumpstart.
That terminal is conductive on only one side, and so are some jumper cables. Be sure you have good electrical contact on both ends of both cables. If voltage at the battery (Mendel's good suggestion to check) is good, the problem is somewhere else.