Need Help Repairing a Gen1 Prius with P3000 and 3006 code

There is a collection of 5 UTube videos available that will aide you in removing and servicing the HV battery. I just completed that task and checked all the cells, cleaned the copper connectors, etc. It could be you have lost a cell or lost the contact between one cell in module 4. The UTube postings are "Toyota Prius - Triangle of Death - -Battery Repair (Part 1of 1)" and so on up to Part 5. Did this in less than two days. Job is not difficult, just be careful, follow all instructions. The battery weight is really the only major issue. Looks like only single cell, so check its contact with companion cell. Actually you needn't pull all the cells out as once the copper contractors are removed the cells are individually isolated from each other so you can check individual voltages. If there appears to be corrosion under the cells you may have to remove them to clean the affected areas. When cleaning the cell post I used a non-metalic brush. Don't want to short across opposing post. I hope this helps. I'm still learning on these cars, but if I can be of any assistance, please post. Any of those out there that see a negative in any of this info, please mention it. There are many out there that are far better than I at keeping these vehicles running. I definitely welcome any help and corrections. All of this is a learning experience. Thanks to all. Peace

 

Not really a correction more a clarification, but hopefully helpful. The only comment I'd make is on terminology that is used on PC, which helps lessen misunderstanding and can make communication easier and/or clearer, and hopefully consistent across posts.

	Term	Definition
1	Cell	Smallest unit of a battery.
2	Module	Technically a battery of 6 cells. The smallest practical unit of a Prius HV (hybrid vehicle) battery.
3	Block	Module pairs monitored by HV battery ECU.

The Gen 1 Prius HV battery is made up of 38 modules or 19 blocks connected in series.
The Gen 2, 3 and 4 Prius HV battery is made up of 28 modules or 14 blocks connected in series.

Hope this helps.

 

Thanks for the input. So each cell has two modules, is that correct? Sorry I had the terminology reversed. As I said, I'm still learning vehicle so this helps me in making clarification. Really appreciate your help. Can I assume the rest of the post is correct as I don't want to mislead anyone. Those are the steps I took in clearing P3000 and P3009 codes. You folks have been great along the way educating me on caring for my Gen1. Thanks again for the input, I really appreciate all the help. Peace.

 

No, , each module has 6 cells. You were calling modules cells. Each block has 2 modules.

You can't work on a cell, unless you cut open a module, as the modules are sealed units.

 

I think now I am beginning to get it. Each module should then test to approx. 7.75 volts, giving the block (with two modules in series) a total value of approx. 15.5 volts. I checked each module (38) and all tested 7.79 or slightly higher. Sorry I used the incorrect terms. At least now I hopefully have it figured out. Thanks for you patience. Peace.

 

No need to apologise, the motivation is to inform and spread the knowledge.

Modules have a nominal voltage of 7.2 V or 1.2 V per cell. The reality though is that in use the cell voltage can be anywhere from 1.28 V (40% SoC) up to 1.36 V (80% SoC). – 7.64 V and 8.16 V per module respectively.

Module voltage can go as high as 8.64 V when balancing and I have seen, in techstream, modules being charged up to over 10 V (20+ V per block) by the car.

Peace to you too.

 

Thanks also for the info on possible voltage readings. That will be great in the future as I evaluate the HV battery. I keep a spreadsheet on the vehicle and all checks and repairs are recorded with corrective actions taken on issues. Again you folks have been super and I try to pass on anything I learn and can verify. Thanks again. Peace.

 

If it were me I would not assume any repairs until the battery was removed and all modules were individually tested for voltage value. The test should verify which, if any, module in block 4 is the issue. Although not likely, there could be a problem in the contacts between the modules of Block 4. This way you can isolate the exact problem. Be sure to clean all contacts on reassembly. Based on the reading of the remaining blocks, once you correct the defect pertaining to Block 4, reinstall the battery and see what happens. I might suggest placing the 12 Volt battery on a maintainer (low amp output - approx.1.5 amps) while you perform the HV battery repair to ensure proper operation during restart. The vehicle itself will do a good job bringing the HV battery up to speed, if there are no other issues. The best approach is "to keep it simple", and not over think anything. Hope this helps. Peace.

 

My Gen 1 battery issue was the modules leaking at the posts on several of them. Cleaning them will make it pretty, but the leaking ones are the ones to replace. Had I known about the tendency for the Panasonic Gen 1 batteries to do this, I would gladly have paid the $100 diagnostic to run and check the voltage levels of the modules before the 100,000 miles came up, and thus would have probably had Toyota pay for the replacement, instead of me at 140,000 miles. The photos the guy showed me before the replacement looked like it had been leaking for a good while. I think it was $1200 for the battery and $800 labor I shelled out.