Intermittent Master Warning and Hybrid Failure Issues

Aloha,

I am a newbie here. I just bought a 2nd hand Prius off of someone from Craigslist on Sunday. Its a 2006 Prius with 171,000 miles. The car seemed to run fine with no issues on Sunday. I woke up to take it to work on Monday morning and the dash lights where the speedometer is was completely out. The back trunk door was also locked and would not open even though I pressed unlocked from inside the car and from the key fob. I manually unlocked the trunk from the inside then tried unplugging the negative wire from the 12V battery and replacing after 1 and 10 minutes. It did not fix the problem.

The car was still able to run (or so I thought) with the dash lights and trunk not opening so I decided to head to work. I got onto the freeway, was driving for about 10 minutes then noticed I was having to push harder on the gas pedal in order to keep my speed. I was pushing the pedal to the floor and barely rolling on the freeway so I pulled over and threw on my hazard lights. I noticed the Master Warning light on the dash and also the Hybrid System Failure like on the multifunction display. The air conditioner also started blowing hot air at this point as well. I called a tow truck and was towed home.

I charged the battery for about 12 hours. I couldn't figure out how to test the battery before charging. The dash lights were now on and bright and the trunk could open. The car started fine but the Master Warning light and Hybrid System Failure icons were still on.

On the next day, after reading a bunch of different threads, I tried to self-diagnose the battery. I did the MCD/headlight test to check the battery. The battery checked out fine and voltage seemed to be perfectly within range. I went for a drive around the block and everything was good for a few minutes then the Master Warning and Hybrid System Failure lights came back on. Something new this time around was the Brake System light also came on too ( circle with exclamation mark inside and parentheses on outside). I checked my manual brake and it was not engaged. The toyota manual suggests to stop driving car immediately if this light comes on so I pulled back into my drive way. I trurned the car off and on a few times and sometimes the warning icons come on and sometimes it doesn't.

Any thoughts or suggestions on where to start? I tried to call the guy I bought it from on CL but once I mentioned the car was having problems he changed his number. I'm assuming he knew of these issues and just didn't disclose it all to get it off his hands and make a little $$$.

Thank you in advance for any help!

-Celeste

 

Thanks for your reply. I'm going to try replace it as it is the cheapest intervention at this point to salvage what may be left of this car! Mahalo!!

 

Thank you for your reply! That hybrid battery replacement is my worst nightmare! It's $5000 to replace! I'll look into the other things that you suggested as well. Mahalo!