So My 2001 Prius (Gen I) HV Battery Died The Other Day...

Let me preface my thread with some info. I'm 32/F. My Prius is a Gen I (2001), I bought it third-party with 83.5K miles in 2007. It has 215.6K miles on it today. I just put new tires and new struts on her this year. The CEL has been on for a couple years with P0420 (catconv bad). Don't judge me.

Ok so...

Sunday Oct 12 (2013):
We had just pulled into a parking slot at our community park to practice some softball when the Christmas Tree Dashboard Lights of Hell came on --- "Triangle of Death", "CEL" (of course) and "PROBLEM" warning on the MFD. I limp-mode-ed home and pulled the codes with my Craftsman OBDII --- P0420, P0171 (MAF Sensor bad), and THEN P3006 (HV Batt SOC Uneven). Ok. So after having a few massive cows (my Prius was supposed to last at least 3 more years, until I have my house paid off and can buy a new Prius), I started reading on these wonderful threads about the DT codes and how people have fixed their own HV batteries. This gave me the confidence to try and wrangle this thing myself. I like to think I have some technical inclination, I like to take things apart and fix them (but never anything that carried 270VDC+), so... I gave it a shot - I'll be damned if I'm giving my local stealership $3500 for a new HV batt + install.

With the help of many hours of watching YouTube videos on how to get an HV battery out of the car and replace a module, I got to work. I took my battery out of my car (by myself, ugh, 100#+ it was heavy) and set it on (2) solid CMU blocks so I could access the module mounting bolts. I tested each module with my multi-meter and found that #19 (from the non-ECU side) read 6.64V. The others ranged in voltage from 7.91-7.82. I know this is sort of a blind guestimate to their quality; I don't have the equipment or time to measure their capacities by charging and discharging them.

I ordered a replacement module from eBay and waited patiently. I also ordered a new MAF sensor and air filters, which I replaced easily. I spent more money using other people's cars and filling up their gas tanks than I did on a replacement module. lol. Once it arrived I took it out and measured the voltage. It matched the exact reading of the one it would be paired with (7.61V) - I took this as a sign from the car battery gods and hoped for the best.

I removed the existing mods and replaced the bad one with the one I bought on eBay, put the mods back in, and put everything back together. I had my partner help me put the battery back in the car and hooked it all back up to everything. I did not balance the battery ("Ain't nobody got time for that." lol. Seriously though, I know it's recommended). I hooked the 12V aux batt back up and the overhead lights came on. I turned the key one click and nothing, turned it another click to the "aux" position and the dash lit up like normal, after a minute or two (which seemed like forever) of robotic servo noises from the car/HV batt, it quieted... <heart pounding> then I turned the key to start it................ and nothing happened. And by nothing, I mean it started normally and no warning lights came on!

I sat there shaking with adrenaline for a moment or two and then put it in "D"... no warning lights. I drove her around the block about 2 miles... no warning lights. The next day I tightened down the battery mounting bolts and drove her 40mph, 50mph, 60mph... no warning lights. Today (Oct 28th 2013) I drove her to work for the first time in 2 weeks... still with no warning lights. I am hoping to remain warning light free... for at least another 60K.

So... I want to thank everyone on this forum who has posted about rebuilding their HV batteries - you provided a lot of insight and confidence; and so far saved me a lot of money.

To see the pictures of my battery adventure you can access them via my Facebook page: Leslie Hopkins | Facebook

Thanks again,

Leslie

 

Thanks scotman27. Your thread "while i have the HV battery out of my gen1" is one of the threads that educated me on tackling this project myself... so, thank you!

 

For the non-Facebookers. (I didn't know that it was possible not to have a FB account. J/K) I hope this post isn't too huge.

Plug of Doom

Empty trunk/12V batt disconnected
Seat removed/battery exposed
Hit the bumper with the battery when I removed it - oops
Battery removed, sitting on 2 solid CMU blocks for access of the module hold-down mounting bolts on bottom (subsequently in the background - seats and all the crap that was in my trunk <sigh>)
Battery, lid off
Bad module measuring 6.64V Module replacement

Then reverse the process.

 

Yep, that post was huge. Sorry. I dragged the corners to make them small while I was uploading but I guess it didn't listen to me. Lemme know if you want me to resize them.

 

Thank you for the compliment.

The most difficult part of this process MENTALLY for me was turning the key after I re-assembled everything. I just KNEW that my car was going to blow up and I was going to die after ALL that work I had done. Obviously, that didn't happen.

The most difficult part of this process ANNOYINGLY for me was undoing all the flipping bolts that hold the battery modules in. And then once re-assembled, getting the battery pack perfectly aligned in the car was a P.I.T.A. - a two-person maneuver.

Otherwise, this is not a hard project. It's time consuming, but not hard.

It would have been a LOT more tolerable if the module had chosen a better time to fail other than in the middle of DEAD WINTER when it was 0 to 20F EVERY DAY.

 

UPDATE:

• Dec2013: I had another module fail around Christmas Eve (about 2 months after the initial module failure and replacement). Luckily I was on shut-down at work, so I didn't need my car. I took the pack out, replaced the bad module and off I went again.

• Feb2014: My car was "acting funny" again. I feel so connected to my car after servicing the battery pack the first time, that whenever it "feels weird" to me, I know it's about to do something crazy. lol. I took the "lid" off the pack, measured the individual modules and noticed I had 2 high voltages in the same block... so I took the pack out and rearranged the modules in a more even distribution of voltages.

• Mar 4, 2014: Turned over 220,000 miles.

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• Mar 15, 2014: I may or may not have left my door ajar after I got done vacuuming my car and it sat there for about 16hrs, so I had to replace the 12V Aux Batt ($190 @ O'Reilly's p/n: 'PRIUS'). After some hacking and shoving, I got the batt in. It's not a match to the OEM, so it took some modification. The terminals are swapped on this one. And... back on the road.

• Mar 23, 2014: Replaced the cassette deck with a "new" (salvaged) one off of eBay because my original clicked when it played tapes... and by tapes I mean my .mp3 cassette adapter. lol.

 

I don't know. I take it to Plaza Tire and they do their magic changing the oil and rotating the tires.

They've never mentioned anything about burning oil.

 

Crap, I meant Plaza Tire. I changed my post above. Sorry. lol.

I change oil and rotate tires every 5K. Thank you for the advice... I will start checking on it !!

 

Yes. And like $35-40/ea. Equivalent to a tank of gas. lol.