I have a 2007 TCH with about 143K on it. We got the car from my father in law when it started showing a "Check Hybrid System" at 135K. He brought it to the dealer (he only goes to the dealer) who pulled a P0A80 code, and he was told that the cost of the repair was more than the book value, so he decided to purchase a new Prius and gave us the Camry. Anyway, the dealer had told him that one cell module was bad, so I picked up a replacement (used) on eBay, figured out which one was bad, replaced it, and all was good.

Fast forward to a few weeks ago when we started getting the Check Hybrid System alert again. I figured out we had another bad cell, so I ordered another module on eBay, found a cell module that was down by about 1V, replaced it, and thought that was the end of it. However, I still got the Check Hybrid System.

So I got a BlueDriver OBD II reader, and it gave me a bunch of codes:

1. P0A09 DC/DC Converter Status Circuit Low
2. P0A0D High Voltage System Interlock Circuit High
3. P0A80 Replace Hybrid/EV Battery Pack
4. P0ADC Hybrid/EV Battery Positive Contactor Control Circuit High
5. P0AE0 Hybrid/EV Battery Negative Contactor Control Circuit High
6. P0AE6 Hybrid/EV Battery Precharge Contactor Control Circuit Low
7. P3000 Battery Control System
8. P3105 Lost Communication with Battery Observation

I also got these other codes:

1. C1259
2. C1310

I'm thinking I may have a bad connection somewhere, but I'm not sure what to check. Any ideas?

Thanks!

 

I'm going to answer my own question:

Just for the hell of it I decided to clear the codes using the ODB II analyzer, and that seems to have fixed it, even though the first time I fixed the problem, I didn't need to do that. The only thing I can think of is that when I fixed it the second time, I forgot to connect the fan when I first started it.

 

I hope that will not become a pattern for your HV battery.... Did you clean copper buses connecting modules? That is said to be very common cause of module failures. Just like rusted battery cable terminals.

 

I did not, but I guess I should before I put everything back in. Thanks.

But this raises another couple of questions:

1. What's the best way to clean (I'm thinking muriatic acid, then a running cold water rinse)?
2. Has anyone used those anti-corrosion sprays that you can buy to use on a car's 12V battery to protect the bus bars? I've never used them, and I'm concerned that the spray would get into places I wouldn't want it to - the hybrid battery pack is a lot more sensitive than a standard lead-acid battery.

 

Bad 12V produces multiple errors that don't make sense. Load test 12V with a real load tester to confirm it's good. Most of those little sh!tty hand held electronic ones are a joke. $ .

Your odd collections of codes SCREAMS bad 12V to me.

Be advised that you're likely entering into an extended game of "whack-a-mole". You should provision for a module replacement at least a few times a year. You can minimize it by also replacing anything outside of a 0.05V range. The exceptions are the end modules. They tend to be 0.05V below the "typical" for the pack, and they are typically okay that way, e.g., you have the bulk of modules at 7.68 to 7.73, the ends at 7.63, one in the 6s and one at 7.53. Replace the 7.53V too. It's the next to fail - sooner rather than later.

1. Yes. Dilute the typical pool acid variety (~31%) by 50% in a glass container. Soak/agitate carefully for 60 seconds - AVOID fumes and skin contact. Rinse thoroughly. LIGHTLY scuff module terminal side of bus bar with with steel bristle brush. Lightly scuff any nuts with excessive corrosion. Note that 99.9% of the current goes through the contact area between the terminal end and where it contacts the bus bar. Little else matters. Wiping/removing any residue from the terminal ends is also recommended. It's common to get some whitish "dust" in the area.

2. Absolutely not. Don't even consider it. Leave them naked and make sure you torque the nuts to 48 in-lb.

Lastly, while you didn't mention it, you will find tales of people fabricating harnesses to put modules in parallel to help equalize their voltages. Don't bother with this. It is a complete and total waste of time. It accomplishes absolutely nothing meaningful. I have conducted detailed testing to demonstrate this, and very little current actually flows between them as their voltages equalize almost immediately, and the current flow slows to a trickle. I have taken modules that were completely empty and coupled them with a module sitting at 8.2V (fully charged). After 24 hours, about 1000mAh transferred to the empty module while the fully charged one dropped into the low 4000s. Their resting voltages were identical, but their capacity was dramatically different. The moment I applied a load to the 1000mAh module, the voltage plummeted. This is what happens in the car - the ones at low charge plummet and the voltage disparity returns.

While voltage is important, it's the voltage due to the state of charge AND its response to a given current that matter. Resting voltage is almost irrelevant.

Good luck.

 

Oh good, I was hoping S Keith will kick in. He works on hybrid batteries, so he knows what he's talking about, OP. I think, punch line was - 12V needs to be replaced or, properly tested first.

http://www.pacificpowerbatteries.com...aq/dcfaq3.html