Traction Battery indicator and triangle of death

It just depends. I've had these symptoms b4 but, they have not been consistent. What I think is the biggest indicator is, 1) fuel economy (has it changed) and 2) Do the warning indicators reset and come right back? If there is a problem, the warning lights/dtc's will come back consistently after being cleared. 4-5 cycles of the key will typically clear the lights. Or you can disconnect the neg terminal of the 12V battery to clear the codes. I experienced this last summer on a really hot day (virtually the same symptoms), I turned the car off, then back on and it ran normally. I reset the warning lights by cycling the key off/on 5x and haven't had a problem since. I or someone in my family drives the car nearly every day. My experience w/ the Gen I is that it can be finicky.

I've also experienced opposite symptoms (once) where the ICE ran all the time and the battery charged to 100%, no warning lights (I have no idea why this happened). A cycling of the key fixed this as well.

That is not to say you don't have a problem but to me (maybe to my deficit), you need to see the warnings consistently (or at least semi-consistently). Coolant bubbling in the reservoir is a good sign. I would recommend checking/replacing the 12V battery though.

 

The coolant pump is always running, do you mean you can hear the fan behind the back seat that you normally never hear? If it is the fan (stick your ear at the weird air outlet on the back pillar) and it is very loud, that points to the traction battery getting very hot (ie. dead modules).

The battery SoC jumping around also points to a bad module or pack. It could throw a red sign if the battery voltage w

It also isn't good to have air in the inverter coolant, so it can throw codes for that reason, if the inverter gets too hot.

I would run to an auto parts store and read the codes with an OBD-II reader to see if that gives any insight if it just happened, they will clear after you start and stop the car a few times.

 

The battery fan running indicates one or more failed modules that are overheating. It is a strong indicator of a failed (failing) traction battery. Sad to say, the standard OBD scanners seldom handle reading the detailed codes from the traction battery ECU . . . the ones that show the module-pair voltages and temperatures.

Joedirte gave you excellent advice and I concur.

Bob Wilson

 

Oh... well... that's different. Yeah, only go to auto parts place if they are really close, but it might give something, probably worth paying Toyota for a prognosis. Sounds like one or more battery modules are now bad and heating very quickly and heating other modules. The fan doesn't go to screaming loud unless you are really putting a lot of current into/out of the battery, or one module is bad and constantly heating itself.

One question. Say you drive for 5 mins, put it into P, how long does the ICE run for before it shuts off?

It may only be a few modules, but likely you are going to have to start reading about getting a new battery pack from somewhere or looking into doing it yourself.

 

As you've seen by the heat, one or more modules are in self-discharge range and just generating heat. From this graph: http://batteryuniversity.com/_img/content/cycle3.jpg which is NiMH 950mAh pack. [1]

I might try force charging the battery just to see if you can coax some extra capacity out of it. I wouldn't recommend it and you probably shouldn't do it, and it could hasten the demise or overheat the module, but my view is the module is toast anyways. But if you started the car and waited 2 mins, then put into D with brake FIRMLY on the brake pedal then apply moderate pressure on the gas pedal and you will hear the engine revving. I would only do this for a minute and stop if you hear the loud battery fan kick in. I guess if the module is complete dead, you will see it jump to green/100% on the battery bar quickly.

 

Well, P3006 is a good sign (for me anyway) because that means you should be able to determine which module(s) is/are bad. If you're mechanically and electrically inclined, this is not hard to do and requires few tools. You just need to access the battery and measure each module with a DMM. Does this sound like something you can do?

Beware: High DC voltage present.

 

If you have time, pull the battery cover and be reasonable careful (ie don't touch or measure from one end to the other) and just measure all 38 module voltages, (or just the 19) and see if the end connectors have corrosion on them which might explain/need cleaning up.

You could also pay Toyota $50 or $100 to print out voltages and module resistances and any codes.


P3191 means the ICE didn't start for some reason. Subcodes might tell you more.
This might be an interesting read (but may not apply to your situation)
Prius 1st gen - P3101 & P3191 part 2

Another case study which probably does not apply to you:
2001 doesn't like being parked on slopes overnight? | PriusChat

 

AFAIC, the reason you got P3191 is insignificant to the 3006 and your particular problem. That was probably a stored code from who knows when. I wouldn't put much time into trying to figure out why you got 3191 unless it consistently comes back (which it shouldn't).

And yes, fixing the battery is pretty straightforward as long as you have some electrical/mech knowledge. Just b careful, go slow, check and doublecheck everything you do. YOU CAN DO IT!!!!

 

What are the codes?

Are these from a Prius aware, scanner? The reason is many over the counter scanners do not know how to report the 19 module pair voltages, a key metric.

Bob Wilson

 

Without knowing the codes, the triangle is probably from module imbalance. What was the voltage of the module you replaced? Did you do a balance on the pack at all or did you just replace one module?

I don't believe a long drive would ever "rebalance" the pack. If I were in your shoes, here's what I would try (following info assumes car is warmed up and in S4 mode):
1) Drive the car on a flat stretch between 30-35mph in all electric as long as possible (until the battery is as depleted as the HSD will let it get. You will know this when the battery indicator is at 25% and the ICE fires up).
2) Drive normally until the battery indicator = 75%
3) Find a long slow downgrade and coast in D until the indicator goes to 100%
4) Drive normally to home and reset the codes

If after all of this the codes still come back (which I'm betting they will) and the codes indicate HV battery imbalance, the only way to clear the codes will be to pull the battery back out and balance the whole pack.

It should be noted that this is what I would try. I'm not a mechanic, I'm not smart and I'm not an expert. Taking advice from someone from KY could be dangerous to your health and your cars health. Although I don't see how this could hurt your car, I also place a low probability in it fixing your problem.

 

That's so awesome. I love to hear stories of a $38.00 HV battery repair (that's about 25% of the cost of a new aux battery!!!!!!!). If/when my HV battery fails in my 01, I will implement nearly the same procedure.

PS: Where did you get the module from?