Rebuilt 2006 Prius Battery

The air bag controller ECU has nonvolatile memory for sure. There must be others.

To the OP, the recommended code readers are all Prius specific. Just about any others are suspect, in that they read incorrect codes, or don't read all the ECU's and leave you guessing.

 

Can you list the Prius specific ones, if you aren't referring to Toyota TechStream? Thanks.

 

Torque app for Android phones only reads data and resets codes. ScanGaugeII much the same. Autoenginuity has more function but some complaints about stability. The mini VCI on eBay is a must have for any DIY person. There must be others, more professional grade and expensive that cover many models, but only used in shops.

 

Are you referring to the miniVCI that comes with a TechStream "like" DVD? I see some that say 2012 in the title/description. Would this suffice?

 

Not sure which models are covered. GenII for sure.

 

Congratulations Brian! We expect you to frequent the site and share your hard earned expertise. Also, it's good to know that the Prius can save itself from a direct short. I don't think anyone tried this before.

 

Hello Brian, just wandered onto this whilst looking for info on my HV battery problem and noticed something that does seem at odds with my wiring (2004). In your video it appears that you have wrapped blue tape on one high voltage lead and black on the other. These leads have shielding braid and it looks like, (in my case anyway) these ends are meant to be earthed to the battery case. In fact mine has a thin shiny aluminium strap that goes from one of the case securing bolts, across the 2 orange leads at the end of braid collars and on to the other case securing bolt. When all tightened down there is a real good earth connection. Check it out. It maybe the technician when tightening all the connections may have penetrated the tape allowing it to earth. But Hey, I could be wrong.

 

You might be able to give me some advice. Red triangle of death and enough lights to convince me the traction battery was dying. Pulled it out a week later, after swatting up on how to change the modules, off with bus bars and on with my volt meter. 22 modules at 7.80, 3 at 7.79, 2 at 7.78 and 1 at 7.81. Took the data to Toyota and they agreed with me that these numbers looked fine. There was a bit of sulphate around, I cleaned this up and put it back in. No improvement. Drove to Toyota, on to their scanner. 11 of the 2 module blocks were 16.2 volts, but the other 3, (blocks 1, 2 and 3), were 0.19, 0.19 and 0.04. Toyota say a new HV battery will do the trick. It so happens I have a complete set of batteries so I am wanting to swap out the bad for the good. But where is block 1? Is it at the ECU end or at the other? Are the blocks sequential or are they all over the place? My voltmeter test still shows they are all good. How do I tell which are the rubbish ones? Do I need to do my voltmeter test with the module under load? If so, how much?

 

It looks like your module voltage sense lines have a bad connection on the three module pairs that read low. Check that first since your readings on the modules looked good.

JeffD

 

Niol,
jdenenberg is giving you excellent advice. Please read and head. Your batteries are fine. Think about it, how can a battery read 7.8 on a meter (right at the battery) and 0.19 on a remote readout. The obvious answer is the sense lines. I tell you this b/c I hate to see you go thru all the trouble of changing your battery and finding out you still have the same problem.

 

hi briansterling, do you mind posting quide on how you replaced two cells and balanced the cells? Regards

 

Re: Toyota's diagnosis I need a new Traction battery.
Thank you gentlemen. I was puzzled also when I asked Toyota, "How come I get 7.8 v on my meter at the battery and your machine tells me 0.04V. Their reply was that it was because they were doing a "proper" test, under load with MG2 and MG1 kicking in. I was sceptical and asked whether it could be the ECU. "No way, the ECU works or it doesn't and clearly it is communicating. Buy a new battery!" I still wasn't happy, particularly as the service manager had told me the battery had 36 cells instead of 28 and when reviewing my list of 7.8 voltages told me the problem was evident, they should be 13.2 volts. His offsider cautioned me about touching the battery because it had over 500 volts in it, and I had to show the technician who did the test how to properly reinstall the service plug. Thanks to your replies, which made perfect sense to me, I have got the battery out, removed the bus bars, sensor wires and ECU. I pulled the 22 pin orange plug (that has 15 wires), from the ECU and therein lies a black mess with 1 pin melted. About to enter the battery ECU world to see if it is salvageable. Any further knowledge advancement really appreciated.

 

Those techs are clowns. I think they should audition for the circus because they have no business working on cars. It sounds to me that your ECU is working (the one thing the tech said that is right). Get those wires fixed and your problem should disappear.

Let me see if I can figure out what pin 1 signal is. Is that the only pin that has problems?

 

Actually when I cleaned the plug up properly there were 2 pins on the ECU plug that were missing. I had a spare wiring loom with the sensor wires so I was able to use that. As for the ECU, I opened it up and I could not discern any visible damage with a magnifying glass apart from the pins in the plug. So I followed the pins into the circuit board and luckily they were a generous length and stuck out the back of the board by 1/8". This was sufficient for me to solder on two new wires which I insulated well and led them out of the ECU through a hole (insulated), that I drilled in the back of the ECU case. I reunited them with the wiring loom using bullet connectors in a convenient spot adjacent batteries 23 and 25. They fitted nicely in the loom holder which snapped back over the increased volume with no problem. Reassembled every thing, battery back in the car, checked my life insurance and pushed the Power Button. Perfect. Straight into life, Contactors click, Ready light On, All warning lights gone, ICE starting normally, driving like new. My heart is doing more RPMs than MG2 in the Prius V. My first drive of about 10 miles returned 63 mpg. (Ha Ha - designed to make you sweat - I am in New Zealand and our gallons are bigger than yours!) Thank you for the sensible advice. It has beaten the computerised boffins with good old Ford Model T logic.
Cheers, Niol

 

Good for you. !!!

 

Glad that we were able to help you. consider getting a salvaged battery ECU to clean up your repair. I have a spare 2004 ECU, but it probably is not compatible with a 2012.

JeffD

 

No matter how complex technology gets, nothing can replace logic and nothing ever will. Basic, logical troubleshooting techniques will always be king.