2010 Prius Ran Fine, Suddenly Won't Start
 

A little background on this car:
We were hit in a parking lot in September, damaged the rack and pinion steering and outer tie rod end. We didn't have the money to have it fixed until early December. It's been running again about a week now. It still needs a front end wheel alignment, so the traction control light is on. Also, the clock spring was likely damaged during the repair, as the horn doesn't work and the display controls on the steering wheel don't function. The rear door was damaged in the impact, leaving a gap that rain water got into during a couple pretty impressive storms before I was able to fix the damage. THere's still a small puddle under the front seat, but it's a lot smaller than it was before I started clearing it out. I'm getting it dried out as quickly as I can.

I did the steering rack replacement myself, so I've no one to blame but myself for the clock spring being damaged.

The current problem:
I had to go about 16 miles from home to my daughter's apartment. The car started and ran perfectIy, but the Check Hybrid System was displaying on the dash, as was Oil Maintenance Required. THey both came on about two days ago. I plan an oil change in the next week, if I can get the car running. I parked on a hill with the front of the Prius facing down the hill. About 30 minutes later I returned to the car, but when I tried to start it all the dash lights came on but didn't go back off again like they normally do. The dash displayed Check Hybrid System, but the car would not start and would only shift into Neutral and Park.

We tried jump starting the car, it would not start. My son found a sort of "reset" in the manual, so we followed those instructions:
1. Engage the parking brake
2. Put the car in accesory mode
3. Depress the brake pedal.
4. Hold the Start button for 10 seconds.

We tried this several times. No result.

We cannot afford a mechanic, and I can find my way around a gasoline engine, but I know nothing about hybrid systems. We do have access to a code reader, but it wasn't with me when the car refused to go.

I wonder if anyone here might have suggestions on what I might try to get the car started or what might be causing the problem that I could look for when I get back to the car in the next day or two?

Re: 2010 Prius Ran Fine, Suddenly Won't Start
 

Likely a high voltage isolation fault, P0AA6 due to a physical leak in the battery, insulation breakdown of the motor windings in the transaxle or A/C compressor, isolation fault in the inverter or a short to ground in the HV main wiring harness.

Disconnect 12V for a full 2 minutes. Reconnect. Attempt to start car. Hopefully, you can clear the code with the 12V disconnect and resume driving. if "check hybrid system" returns, DO NOT TURN THE CAR OFF until you are done driving as it will be disabled at next start attempt.

Re: 2010 Prius Ran Fine, Suddenly Won't Start
 

Thanks for that. I got it started by resetting the codes with the OBD2 reader. My wife thinks it was just too cold for the car to start, but I'm not sure. The code reader said the hybrid battery needs to be replaced. It starts just fine now, but I'll be testing the battery ASAP just to be sure.

Re: 2010 Prius Ran Fine, Suddenly Won't Start
 

Never seen or heard of a Prius unable to start due to low temp.

P0A80?

Re: 2010 Prius Ran Fine, Suddenly Won't Start
 

Yes, that was the code. Sorry, couldn't remember it when I posted earlier.

Re: 2010 Prius Ran Fine, Suddenly Won't Start
 

Gen3 batteries fail via a long, slow, permanent loss of capacity due to heat/cycle damage. It's a certainty that you need a replacement battery or be able to screen and replace up to 3/4 of the modules for a decent DIY repair.

Clearing the codes and babying it may get you by for awhile, particularly in cooler weather, and don't touch the EV, Power or ECO buttons. The no-start issue is a concern. A P0A80 won't cause that, or at least I've never seen it, and it's not described as a potential outcome in the repair manual.