I bought a used 2007 Prius 136,000 miles dash lights came on the next day. The big red triangle, the check engine light, the vsc and the (!). I have replaces the 12v battery. No changes. My car runs on the gas engine all the time. From start to shut off. trying to figure if the charging system is working or not. Took it to airport Toyota they said I need a new HV battery.HV failed block 5. Is it safe to drive? Is the car worth fixing or should I sell it? Thanks in advance.
You can also just replace block 5 with 2 new (used) modules. Less than $100 in parts, not sure about labor. I'm pretty sure Toyota won't do it though. Probably shouldn't keep driving if you can help it to avoid potentially degrading surrounding cells. I'm in a similar situation, with one of my blocks being out of balance. I'm hoping the Prolong kit will fix it so I don't have to tear into the battery. I would get a cheap OBD bluetooth scanner and use the Torque Pro app ($5) to see all the voltages and codes for yourself. I use this one. I also tried a cheaper one (orange and black sticker) but it was unable to read the voltages.
Hope you didn't overpay for this car. It's risky buying an older Prius - as you have just found out. The fact that you took it to a dealer indicates that you might not want to do a repair on your own. The dealer price for a new pack looks pretty good if it includes installation. If not, you have a more difficult decision to make. How did you find out about Priuschat? I know it's no help now, but you should have searched on this site or asked us about the risks of buying an older Prius before you did.
The best option is a new batt from Toyota or on this site we have a seller of a clone, shall we say. Assuming you are not a car geek you will need to find someone to help install. One approach if you have time is to call Toyota USA for goodwill assist on price. Worth a shot but no guarantee.
I would not buy a prolong kit with the new prices of batteries now. The kit is nearly half the cost of the new battery and you'll have to "hope" it keeps your battery healthy or you'll still end up buying another battery. A new battery however will last 10 years without any maintenance. A no brainer.
Because your HV battery pack is too weak to permit it to start the gasoline engine every time your Prius is at a stop. The stop-start feature will work again once you get a remanufactured or new pack (that latter is the much better option).
