Help...first timer here. My 2011 wont start. The check hybrid system light came on, so I disconnected the 12v and let sit. I hooked the battery back up and the car was fine for about 500 miles. Couple weeks later the check hybrid system message lit back up so I parked the car till I had a chance to dig a little reaper into the problem. So I bought a scan tool to see how the hybrid battery was performing, the car has 208k on it. When I plugged in the scanner and tried to start the car to check the system it wouldn't start. I checked the 12v battery and the car showed it was putting out 11v so I replaced it. Still the car won't start. When I push the start button the ready light won't illuminate, although I think every other light does. Also when I try to put it in gear it tells me to put the car in park to start it, after the car is already in park and I've pushed the start button. The brake lights come on when I put my foot on the break so that system is working fine.
First, did you buy a scan tool that talks to all the Prius computers? Most of them do not. A simple wireless OBDII adapter and a cheap or free phone app will read the codes. Carista is a nice turnkey setup that is rental software, but has a free trial period. Next, does the 12V battery have a charge? Just because it's new doesn't mean it has a charge. And, in fact, you'd probably have been fine with just charging up the old 12V battery, at least for now. 11 volts won't keep a Prius from starting. I've started them as low as 8.5 volts. If yes to the above, plug in the reader and put the car in ON mode (two presses of the start button without your foot on the brake pedal. Then you should be able to get the codes. Some codes have sub codes, and you'll want them too.
Now the car says it's getting 11.5v with the new battery. I did the diagnosis and it's throwing a P0A80 code...hybrid battery I believe. Will the car not allow it to start in this case? I guess I need to find out of I can still do a hybrid check with my scan tool and my Dr. Prius app without it running? Thanks
Sometimes yes and sometimes no from what I've read. There will be other codes that tell you some specifics like which battery block is weak or other details.
Have you charged the 12v battery yet? 11.5v will create problems that are not there. Put a 4amp charger on the batter for 6 hours, then clear the codes, and retest. Or drive the car after charging the 12v battery and then run the tests. Without giving the "new" battery a full charge, you are swatting at nats.
We've got highly moveable goalposts around here. Toyota's Gen 3 repair manual will tell you do a quick check, and put a charge on there if you see below 11 volts. In the Gen 2 manual it was 10 volts. Both manuals are giving conservative recommendations to keep you very well on the safe side of any "problems that are not there". I see here we've PriusChatted it up yet another half a volt to 11.5. The general rule around here is, measure your voltage, report it as X volts, and then someone tells you that X volts will create problems that are not there. 11.5 is low, sure. If I saw it I'd put a charge on. It wouldn't make me reflexively ignore what the car was telling me though.
Forum member @PriusCamper has helped a lot of people with hybrid battery problems and is somewhere in Washington state. Perhaps he will see this thread and comment.
