something for you guys to think about

Welcome to the club:

Buying a high mileage, used car is always a 'pig in a poke.'

I've done it with a Datson 210 wagon but I also bought the maintenance manual and expected (and did) use it. The Datson had a head gasket leak and when I took it off, I found a piece of copper wire had been compressed into the head gasket. But it was a transistion vehicle and lasted about as long as $800 should.

There are no subcodes with P3009 which is a leak to ground. The most common cause is an electrolyte leak to ground.

Could you post all 19 readings?

You have 38 battery modules monitored in pairs, 19 pairs. Each battery module has 6, NiMH cells with a nominal voltage of 1.2 V. To see a 0.5 V difference between the weakest and strongest module exceeds the normal 0.3 V documented in the maintenance manual.

You might consider buying NHW11, 2001-03, maintenance manuals. They often show up on Ebay for a couple of hundred dollars.

Now a P3009 is often caused by an electrolyte leak and humidity can change the conductive nature. It is something that needs to be fixed but this is not a trivial task. You are likely looking at a traction battery replacement.

It would help to verify this is a hard failure versus an intermittent triggered by high humidity. If you disconnect the 12 V battery ground for a couple of minutes, it will clear out all of the codes and your current fuel trim. Reconnecting the ground, start the car, it may run rough until it relearns the fuel trim. But we are most interested in the master fault coming back.

Your profile doesn't give a location. Where are you?

To really understand what the car is doing, you' ll need either multiple visits to the Toyota Service center or a usable scan gauge and there are only a few options. Expect to put up or out $150-$400 depending upon how much you want to commit to this vehicle. The manuals, used, are going to be close to $200.

There is no relationship. It was a little risky jumping another vehicle as there is a 100 amp, fusible link to the traction battery. Still, if you drove away and were able to start the car the next day, it worked. The two battery systems are isolated by a DC-to-DC converter. I've drawn 90 amps and seen the voltage sag to 11.48 V.

Bob Wilson

 

As your OP pointed out, DTC P3009 means a high voltage leak to ground. That leak could be caused by any component handling high voltage, from the traction battery to the traction battery ECU to the battery cable between the battery and the inverter, the inverter, or the transaxle.

It is possible that the traction battery has an electrolyte leak that is causing the high voltage leak, but it also is possible that another component is responsible.

The good news is that your battery module voltages seem OK. If a module was bad, your car should have logged a P3006 code as well.

Art's Automotive has an interesting webpage that explains how they diagnosed the root cause of a P3009 code:
http://www.artsautomotive.com/hybrid-articles/111-prius-1st-gen-replacing-transaxle

 

Ok, check the thread on independent mechanics. That the P3009 came back is not a good thing.

It usally takes 5 posts before you can post images. Regardless, that is an excellent price for the read out. Kudos to them!

I'll give a stab but I'll only keep the elements I feel comfortable discussing:

There are four sensors and the usual problem is a failing module will run hot. But these temperature are 'normal' suggesting it was cooler the night before, the day warmed up and it is up to 63 F.

The DC-DC converter is working fine and providing the normal voltage for the 12 V aux battery.

Hummm, a "0.7 v diff" is not good. The maintenance manual suggests the maximum should be ~0.3 V and would be evidence the leakage has discharged at least one or more modules. As they discharge down, eventually, a reverse charge event and the module is fubar . . .

.15 ~= 15.66 - 15.51 :: where is the "0.7 v" ?
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This chart show the problem:

You can see module pair #10 is a problem. There may be other modules leaking to ground, #5, #9 and #14 are candidates. Regardless, this is not a healthy traction battery. The clock is ticking.

Hummm, having 'done the math,' the only hard error is the P3009. The dV between max and min are not that bad. Where did the 0.7 V come from?

Bob Wilson

 

Re: latest development

This sounds good. The thing to do is watch and see what happens.

You might want to review the thread on the ScanGauge. We're starting to break the codes needed to read out the key data. At a minimum, you'll be able to read the traction battery codes, min and max module voltage, and pertty much any other battery data of interest. You can also use it to tweak your driving style.

Bob Wilson