Disappearing P3009

Yeah, my 2003 threw a P3009 twice last week, and now won't do it again... I'm just thinking that if that's the case maybe I have an "early stage" issue that if I can find now might head off a worse issue later? IDK.

Right, so it's HV voltage leak which could be anywhere in the system, and if I owned a megger (which I don't) would be way easier to get a handle on. (I have feelers out for borrowing a megger).

Trying to keep this short:
- the car is not being driven much these days. I went to starting it up to run just for the sake of keeping the batteries "exercised" and charged. The first time it set was just KOER just sitting idling in the driveway, obviously in Park. Pulled and cleared codes. Next day took it for a drive (10 mins or so). No code set during the drive. Parked, put it in park. The code set again. (Sigh). Cleared codes.

- That was over a week ago. Since then I have driven it a good 50 miles. No codes. More than once I've let it sit KOEO for 5 mins. No codes. I've let it idle more than once in Park KOER 5 mins, and no codes. Last one was KOER in neutral (annoying because it yells at you leaving it in neutral) for 5 mins and no codes.

- The only thing I have not done is sit w it in reverse for a few minutes. However, A) it didn't set in reverse, only in Park, and B) it's always parked nose in and has to go in reverse first thing to drive it, so it's now been in reverse the last few drive cycles without coding out.

Anyway, if any of that rings a bell with anyone, I'd appreciate hearing about it. I think the lack of problems in D, N or R leave the most likely thing in the HV battery. But I'm not pulling it out to hunt a ghost. It is a Dorman reman battery, unfortunately. It was replaced under warranty a year ago July. So it's been in the car (and fine) for about 14 mos. Of course, as a Dorman reman, that doesn't mean a whole lot...

Other codes I got, but I doubt connect to a P3009:
C1259 - HV regen problem which I understand as derivative of some other problem - ?
C1521
C1522 - both 1521 and 22 steering motor. IDK what that's about but I've got no triangle for PS system. I'll look at that at some point.

 

Thanks v much. I'll keep track of the humidity too. (So many variables!)

I'm sure this is out, but I've been wondering about my shifter, except that I don't understand how it works (and my internet searches have not helped me figure it out). It's got to be a part of the HV system in some way b/c the HV battery only gets charge in P D B - as I understand it. So in some respect it must be an HV switch of some kind. But in all of the P3009 threads / web pages I've reviewed it's never mentioned. I've just been led to wonder because mine is "sloppy" - just feels worn and "loose." Sometimes I'll start the car and just the jolt of the ICE starting will will actually click the shifter up a little - like it's being snapped into full P position or something because the sloppy lever didn't put the sloppy switch exactly where it needs to be. So it all just led me to think about whatever it is as an electrical switch rather than gear selector. Electricals are not my strong suit, but bad contacts are not exactly rocket science and do wreak havoc on electrical flows.

In any case, as I said, I'd imagine that's not a thing. But it would just be nice for the computer to make up its mind as to whether I have an issue or not. I'll give it time...

 

I'm actually east of the Mississippi
KO = Key On
EO = Engine Off (not in "Ready" on a Prius)
ER = Engine Running

 

Awesome. Thanks! I did actually buy a FSM, but went cheap, bought a PDF copy via ebay or something and later found out it's missing tons and tons of pages, including a lot of the diag stuff. But the NCF also sounds like something I want.

 

Just an update that it's now been almost 6 mos and and IDK how many miles (couple thousand?) no further problems. I still have no explanation, but it's not humidity as the worst of it in VA comes in July & August. Mine does seem to have a small 12V parasitic draw, and my personal/historical experience with this car has been that 12V problems = warning lights. I have been making sure that the car does not sit and is driven every couple/few days.

Just reminds me of when I brought up the issue of "phantom problems" associated with 12V issues in another thread which was met with some skepticism (Need info on replacing the 12 volt battery, 2003 | PriusChat). But when I referred to phantom problems this is what I meant. If there's an HV leak, then there's an HV leak. Period. It can't heal itself. (Unless it's Christine, but I don't drive it long distances in reverse as I don't like to run down the HV battery that much ;-). So, to me, these were phantom codes.

I've owned the car for a little over 2 years and the only funky times have been when the 12V is run down.

Of course, I'm putting a jinx on myself - the car will code out again tomorrow so I'm vigorously knocking on wood.

 

I'm back just reporting that up until yesterday, I haven't had any further troubles.

But yesterday it threw the triangle again for P3000/P3009. This time it was while driving - about 3 mi / 3 mins into a drive. I cleared it and then today it did it again just a little bit farther into the drive (more like 5 mi / 5 mins). Today was about a 26 mi round trip. The code tripped on the way. I read and cleared before the return leg, and then drove all the way back home without the code returning.

The car does run normally through all of this. No noticeable differences whatsoever. Guess I'll just keep waiting to see what happens.

 

Thanks, but before I go on any hunts for conductive paths I think I'll wait to see whether the computer waits another year to randomly detect another HV leak problem. That is, unless there is some simple way to check things which, as far as I know there is not. As far as I know, if the code sets while in Park this points toward the battery. If not, then it could also be in the MG2 windings or even fluid. Or whatever else. Either way, the last time it randomly set and disappeared was almost a year ago. So for now, I'm waiting.

 

LOL. The computer did literally wait another year (after the first year, so now its 2 years). And the same thing popped up. The car sat a little too long. Threw a P3009. Until I drove it long enough. And then it goes away. In between ... NOTHING! No triangles. It just runs and drives fine with no warning lights or error codes.

But I'll just have to chase down the phantom now, I think. (Even though it's both real and unreal).

I'm in Central VA where it's now very hot and humid. But there's no easy link to humidity. Currently humidity is high, but it's recently been higher than it is now and no triangles in the worse periods.

I can't fuss with it right now b/c I'm on my way out of town. When I'm back I will follow along on the Art's Auto beginning diag procedure (2001-2003 Toyota Prius P3009) even though it's ambiguous about time in each stage.

In the meantime I'm actually just in search of the nitty-gritty, highly technical info on how the computer monitors for HV leaks. In other words, we're talking about the computer measuring volts vs volts or ohms here or there or whatever. Does anyone know what the formula or algorithm or equation - or whatever - is for when and why the computer decides that some volts or ohms or whatever is out of spec?

 

Probably more just by way of info, though observations/suggestions are welcome...

I was out of town for about 10 days which is far longer than I ever leave it under normal circumstances. I took it out today on a "long enough" errand to give it a decent drive (15 miles or so, though I went the "long way" to extend it). It coded out within a couple of minutes on the way out. I got to my destination, cleared codes and started out fresh for home. It again coded out within a couple of minutes. When I got home I cleared again and ran it through the steps as described by Art's Automotive here. LOL. Nothing. Five mins KOEO. (Much longer than it took to set each time today). Five mins KOEN and then KOER. So then I drove it another 10 mins or so and still nothing.

And then (a couple of hours later)... we had a wicked thunderstorm. It was mid-90s today and horridly humid. The storm dropped the temps something like 15-20F in the space of a few mins. I ended up having to go out in it for a minute and saw that the interior windows were all fogged up on the inside. (For comparison, our convertible with a history of a leaky top had no interior condensation...)

So, perhaps I am off base, but my thinking at the moment is that I have a small water leak someplace to the interior. (It has to be small b/c there are no wet spots and car has no musty or moldy smell and I've never seen the interior windows fog up before, etc.) High humidity alone has never seemed to trigger these "episodes." But perhaps if it's been both rainy and humid, it leaks a little, I end up with condensation inside of the car, including the HV battery case and that is enough to trigger the code. Then I drive it, the battery gets all hot and cooks off the excess moisture. So the moisture disappears and the code disappears.

IDK, it's all I've got at the moment. The code is gone again so I've got no testing strategy. But I'm going hunting for some water intrusion, I think.

 

That's great info Ron, thanks. Easy enough for me to take look. I drove it again today and it was fine. No warning lights.