FIRE! no start P3006 - P3016 - P3030 - parts & install ECU + Wire Harness to Traction Batt

Correct.

John (Britprius)

 

I should have added to the above this is why the car cannot balance charge the modules it's self as it never charges the battery to full capacity.

John (Britprius)

 

All 6 cells must be working within every module. The lowest capacity cell within all the modules is the capacity of the complete battery. In effect the 38 modules with 6 cells in each module (228 cells) are in a chain. The weakest link in the chain is the maximum strength of the chain. Not the best analogy but reasonably accurate.

John (Brtprius)

 

The cells within the module have a nominal voltage of 1.2 volts "depending on the level of charge". So the battery has a nominal voltage of 273.6 volts. (1.2 volts x 228 cells)
All of the cells have to pass whatever current "amps" the car calls for to run. This can be as much as 80 amps, and a faulty cell will not only not pass this current it will be reverse charged damaging it further.

John (Britprius)

 

0.2 amps is not much load, but the voltage only dropped 0.07 of a volt so that module could be OK. A better method of checking would be to use a car headlamp bulb as this would give a discharge rate of about 2.5 amps. More than ten times the level you are trying at the moment. A reasonably good module should keep this size of bulb alight for around 2 hours from fully charged to discharged down to 6 volts. Leave the voltmeter attached while doing the test and disconnect when the voltage reaches 6 volts. At this point the module would be considered discharged.
A 20 watt 12 volt bulb would draw 1.66 amps at 12 volts (20/12 = 1.66). At 7.2 volts it would draw a little over half that figure say 0.9 amps. You cannot divide the 20 watts by 7.2 volts because the bulb is rated at 12 volts.

John (Britprius)

 

It has 2 functions.
(1) it monitors the voltage of 17 pairs of modules "14.4 volts each pair" and checks there voltage against each other. Any difference above about 0.2 of a volt will give an error code.
(2) it monitors in three places the the battery temperature "in part to control the cooling fan.

John (Britprius)

 

Those are, in best Japanese-to-English technical translation style, the "Battery Voltage Detective Lines". They are there to help the ECU monitor the overall health of the battery. As John already described, the 228 cells are all in one big series connection. Any charging current in, or power out to the car, is via the two ends of the chain and passes equally through all the cells. But over time, as some of the cells are in worse condition than others, some will be more charged or discharged by the same current than others, so just passing a certain current through the whole battery from end to end does not bring all the cells to the same charge.

The voltage "detective" lines let the ECU monitor the evenness of charge across 19 equal divisions of the whole battery stack. Sometimes, the ECU will detect an imbalance and trigger a special charging cycle that keeps the combustion engine running and charging the battery all the way up to 99%+ and then letting it discharge to the normal range again, which helps equalize things. I've noticed this happen on my car a couple of times (in 6 years) and others on PriusChat have also seen it - if you have a ScanGauge installed you can tell when it's happening. Or, if the ECU decides the imbalance is too bad to work with, it can report the offending module pair(s) as bad.

A note: I wouldn't call this little monitoring harness the "main" wire harness by any means; I'd reserve that name for the fat orange wires that carry the real current.

If any of the voltage "detective" lines break (or drop their little tiny magnifying glasses or the tobacco in their pipes goes out), the ECU will report "Battery Voltage Detective Line Snapped" and maybe even "battery levels are unusually different" - two of the exact codes you reported way back when you started this thread.

Another note ... I wouldn't work too hard at trying to model exactly how problem X might have resulted in symptom Y in this particular case. In your case, you have "voltage detective lines" that not only "snapped", but freaking caught fire. That's a mark of the sort of extra-rare, multiple-contributing-element problem that can sort of defy the usual efforts to piece together a complete explanation of this-led-to-this-led-to-that. You're doing the right thing about it, namely to start by replacing the stuff that's visibly obviously ruined, putting the battery back into decent condition, and ultimately reassembling the car to see what, if any, other problems you might still have.

-Chap

 

The metric system is less confusing, because it has totally different units for mass (grams) and force (newtons). Difference: mass is a fixed property of something, force is applied to something from outside. (What we call weight is a force applied by gravity, which depends on mass.)

Example: if your body mass is 55 kg, it is 55 kg here, 55 kg in a rocket in space, and 55 kg on the moon.
On the other hand, your weight (a force) depends on gravity, so in newtons would be maybe 534 here, 0 in space, 89 on the moon.

It gets all muddled when people talk in pounds, because sometimes we treat pounds as mass units (how many times have you heard that 2.2 lb = 1 kg?), and a lot of time we treat them as weight/force units ("hey, I weigh 120 lb here, and 20 lb on the moon!"). Sometimes we get so carried away with the 2.2 lb/kg rule that we end up even treating kg as force instead of mass ("hey, I'd be 9 kg on the moon!" "no you wouldn't, your mass doesn't change!").

End of story, when people are being careful about what they're saying, they'll tack an f on the end so you know they mean force. (If you say you'd be 9 kg on the moon, you're talking nonsense--or you're really really small--but you can fix it by saying 9 kgf on the moon, which might be about right ... though fans of the metric system would encourage you to just convert that to newtons, instead of taking what everybody knows is a mass unit and trying to make it a force unit by putting f on the end.)

So 48 in-lbf is how hard you'd be twisting something if you pulled with one pound of force on a handle 48 inches long, or four pounds (force) on a handle 12 inches long, or any other combination that works out the same. Or 5.4 newton-meters, which is the less muddly way to say it because when you use newtons everybody already knows you mean force!

-Chap

 

There is a main relay which if I remember correctly isolates the ends and breaks the orange circuit in the middle.

There is a main relay that closes on both ends of the battery and if I remember correctly, also joins the two sections. But that exhausts my knowledge of the traction battery electronics. Fault-isolating the relay is not something I've had to deal with in the past BUT having a fire in that area . . .

The first challenge is to read out the codes from the HV ECU. There is a computer there and if it is working at all, it will return a code tell you what is wrong.

But board-level debug of the main relay and associated circuits, this is a new area.

Bob Wilson

 

The diagnostic codes are your friends. Before you try any other way of "guessing" what the problem is ...

What are the codes?

You won't see voltage at the power cables if the SMR isn't pulled in ... the ECU may have declined to pull in the SMR for any of a number of reasons, that it will be happy to tell you about when you scan for the codes.

-Chap