2001 Prius Inverter Pump

It's not easy to get the air out of the Classic inverter coolant loop. (2G is much easier.) If you don't hear weird noises from the pump then I don't think the impeller is loose.

A few questions:

1. Do you hear air bubbling in the system? (If yes, then you need to continue working on purging air out.)

2. What is your procedure to purge out the air? Did you open both bleed valves when trying to get air out of the system, and run vinyl hoses from the bleed valves up to the reservoir opening?

3. How long have you been working on purging the air out? I recall having to spend around 30 minutes or more to get air out of the system.

4. After you've worked on it for a while, if the coolant flow hasn't been restored, try driving the car a short distance, just around the block, to see if that helps.

Good luck.

 

mine didnt have the bubbling action like it should also, i ended up removing the inverter radiator and pumping some isopropyl alcohol through the radiator and the inverter, a lot of pink crud came out. Its very possible the prior owner accidently put transmission fluid in the inverter coolant tank, clogging it up.

 

I just bought a 01 with 148k and a bad inverter. P3125 only. I am in the process of loacting a replacement inverter. And advice on doing this replacement? What instructions did you use to fix your car? Can the old inverter be fixed?

 

Despite what you may read in the forum archives, P3125 does not necessarily indicate a faulty inverter.

Your vehicle's HV ECU will have recorded a three-digit information code, as well. You need that code.

 

Buddy, I suggest you drive only limited distances until you are sure that the inverter coolant pump is working well and not airlocked.

Colonel, an extensive compilation of available used part # G9200-47071 can be seen at

www.car-part.com

on the part pull-down list select power inverter (hybrid)

If you can get the the 3125 subcode there is (at least) a small chance that this can be remedied with something less than an inverter replacement. OTOH, the subcodes could lead you into the transaxle itself. We shouldn't wish for that.

 

I have already replaced the inverter. The car started right up. My problem now is finding an inverter coolant pump and Traction Battery ECU. UGH! The repairs to this car arent the hard part getting the parts is.

 

colonel 570: Re-involt, in your region, might be able to help with the battery ECU.

 

This thread looks like the best place for my first post. We've been enjoying our 2001 Prius which we purchased a month ago with 176000 miles.

Right after we brought it home, it threw a check engine light. At the time we didn't have an OBD-II scanner, so I checked under the hood, found the inverter cooling fluid level was a tad low, topped it up with Toyota long life coolant ($27/gallon!), and cleared the code by disconnecting the 12volt battery negative cable for 5 minutes. Everything was fine.....until yesterday - a really hot day.

My wife was driving home and the triangle of death came on. But now we have a cheapo OBD-II scanner (CAN OBD II Code Reader) which can read most of the major codes, but not the toyota subcodes. So I plugged it in and found P3130 (with a "$16" subcode - should be either 346 [pump or relay] or 347 [cooling fan]). I cleared the code but it came back immediately.

Let the car sit overnight. Next morning the pump was pumping fine and there was a good flow visible in the coolant reservoir , so I performed the bleeding procedure and a couple of small air bubbles came out, nothing more. So I went for a drive with no problems, and when I came back the pump was dead quiet and no flow was visible in the reservoir! But no codes were thrown.

Went through the diagnostic procedure (I signed up with ALLDATAdiy.com as its cheaper then the Toyota tech site), tested the relay (good), voltage was present at the pump connector, but the pump, she no pump.

Took a wooden dowel, held it against the pump and tapped the dowel a few times with a small hammer, and the pump, she started pump'in.

So the pump has an intermittent failure mode that seems to occur when it gets hot, of course the worse possible time. I think this was the same problem we had initially, as it occurred under the same circumstances.

New pump from Toyota will be here Thursday. Replacement procedure doesn't look too hard, found the thread from Patrick Wong but I think its easier to use the "other" procedure where you remove the bumper cover and headlight - its pretty cramped in there!

 

This morning the pump is not pumping, and no amount of tapping, banging or begging will wake it up

Will be interesting to disassemble it to see what the failure is -bearing, impeller......

 

Please take pictures.

Thanks,
Bob Wilson

 

"Let the car sit overnight. Next morning the pump was pumping fine and there was a good flow visible in the coolant reservoir , so I performed the bleeding procedure and a couple of small air bubbles came out, nothing more. So I went for a drive with no problems, and when I came back the pump was dead quiet and no flow was visible in the reservoir! But no codes were thrown.

That is because the inv. did not reach meltdown temps yet. If you drove it longer and at highway speeds it would be fried. Once you smell burnt electronic smell it's all over.

I too am beginning to really watch for the inv. coolant pump malfunction in our 03 classic, but have still not seen anything wrong -even on 100F days. But the pump always runs fine and you can always see/hear the turbulance in the coolant tank. The last hot day after a 30min. drive I felt the top of the inv. and it was hot to the touch by hand (usually doesn't get this hot) but the pump was running as always keeping it cool enough. A pump failure at this pretemp and at highway speeds would be inv. death for sure! I think it would be well worth it to place a small flow sensor in that coolant tank, then feed the wires back into the cabin to a box w/led.. for example: led on/blinking=no flow, and led off= flow good. This could even be powered by a 9v battery independently inside it's own small box perhaps velcroed to the dash underside. I am thinking flow sensor vs. just a temp sensor. If only a temp sensor in the tank and the pump fails it will not rise temp in the tank, only inside inv. box will get hot. The tank would actually cool off a bit with no flow wouldn't you think? This is why I'm thinking flow sensor here, no flow = goodbye inv.

 

I've thought about trying to detect an abnormal current flow but after looking at Hobbit's disassembly photos, I'm not sure. A brushless motor, the control electronics may inhibit the high currents when a rotor 'sticks' or a bearing fails.

Detecting a pump failure is an interesting challenge but could we just listen for it by turning on to ignition and listening for it?

Bob Wilson

 

I just noticed two interesting signals that may be analog, temperature:

• M-INVT - blue wire, connector H11, pin 11
• G-INVT - blue wire, connector H11, pin 23

It may be possible to tap these lines and monitor the voltages. Using either my Graham scanner or Auto Enginuity, I can probably map the voltage vs. temp curve. However, I would expect it to match the well known engine thermistor curve.

Bob Wilson

 

Why not simply replace the pump? It was redesigned a few years back.

 

That would be too easy!

 

Why replace an inferior part with another inferior part?

The ZVW30 inverter pump was significantly reworked with dual bearings. If I'm going to replace my NHW11 water pump, I want it to be the last time. The part costs won't be that much different and the resulting peace of mind well worth the difference.

Like replacing the NHW11 traction battery. I will go with the Re-InVolt solution before the old style, inferior modules of the original design. Now in my case, I have knowledge based upon testing that is likely to extend my traction battery life. But should it fail, my after-market solution will be the better replacement (unless Toyota gets a clue.)

The irony is Toyota has a public commitment to quality until the warranty ends. Then we get ignored or nonsense answers.

Bob Wilson

 

Again, the Gen I inverter coolant pump has been redesigned.

Actually, the Gen III inverter pump is a completely different design with a completely different control strategy. And I haven't seen a Gen I pump with failed bearings. Have you?

An assumption about one component will not necessarily carry over to another component. However, it has been explained in another thread that we simply do not know whether or not replacement Gen I battery packs have been redesigned.

At present, no data has been presented to support your hypothesis. But I'd rather not see the thread go off on a tangent. The subject is inverter coolant pumps, not used battery modules.