Mig1 and 2 numbers after inverter pump fail code today

It would be a lot more prudent to lower your speed, also if the inverter pump reservoir is low you could top it up, normal operating temp can be checked winth your finger. When running right it is just over body temp. Running too fast is what did it, but the overheating and low level can also cause air in the system, which causes the pump to cavitate. Bleeding the Air out is really simple.

 

Put your hand on the top of the Inverter. It norm runs around 110F so you could leave it on there for a while during proper pump op. Yours will be substantially hotter. Your MG should not be in the 200's either.
So you have no transmission or Inverter cooling and are presently overheating both.You can drive the car till you overheat the inverter to the point of it shutting itself off to protect itself. At that point it throws alot of codes and the car goes dead. To put it plainly you can easily total the car damaging the trans and inverter driving extended distance with no pump.
If you must drive the car put bag of ice on the inverter as often as possible.

 

If you are looking inside the inverter coolant reservoir, you should see turbulence on the surface, indicating flow. If no motion, then there is no circulation happening, which means no pump working.

Those Scangauge numbers are the temperature readouts for the thermocouples in the windings of motor-generator 1 (the smaller one) and motor-generator 2 (the larger one). The numbers you see are in the extreme hot range, just below that which would set a DTC. The inverter is also in that loop, so it is also likely very high as well. While the car may be running OK in the cooler weather, this is not good for longevity, and you should get the pump replaced ASAP. If you haven't had the transaxle fluid replaced yet, it would be good to do so after running it such an elevated temperature.

 

If there is no flow in the reservoir, that should provide an easy diagnosis for any mech!!! Simply show him that there is no turbulence.

If I were you, I would be tempted to buy the inverter pump and some tools and do it myself. It isn't that hard and not many tools are required.

 

F***ing typical. Stealerships just won't replace a part without being absolutely sure that they will be reimbursed by Toyota for the warranty repair. An HV inverter water pump that is functioning correctly will always have turbulence in the reservoir.

Here's a video from Luscious Garage - it's not the best quality but you can see fluid moving. Show this video to the idiot at Las Cruces Toyota.

 

If it pumping you will see the flow. You have to look very carefully because it is not easy to see!Oh and you will not see bubbles. H

 

With a new pump, it's REALLY easy to see the turbulence. It is with the one just installed in mine last month. I couldn't believe the difference compared to the original. And I agree, no bubbles - unless you add some LOL!

 

Hmm, I checked for turbulence on mine in the past two weeks and I can easily see it. My inverter pump was replaced 3/18/11, per my request (given the LSC). Crossing my fingers that it holds up for at least as long as the original...

 

Bleeding the air out of that separate inverter coolant system, should be part of the whole process. Make sure they do that. We have had reports previously where they did not bleed the air out at all OR insufficiently. If the air is not bled out, there will be no volatility, you'll be pumping air!

 

I really cannot believe the incompetence exhibited by whomever is working on your car. Failure of the inverter coolant pump should not be a big surprise since that dealership would have had the opportunity to replace those pumps on almost all 2004-2007 model year Prius in their service area. Those cars were subject of a recent Limited Service Campaign (LSC, aka recall) and one of the links below provides more info.

I have attached a few pages out of the Toyota repair manual. See step #4 which describes how to check inverter coolant pump operation, and note the text: "OK: Coolant is sloshing in the reservoir tank"

What this means, is to look for fluid turbulence.

This is not rocket science and you would be justified in giving the dealership service manager a very hard time for:

1) the tech's lack of ability to diagnose the problem and
2) the very long time spent to resolve the problem.

If you are charged for this repair, I suggest you write to the Toyota Customer Experience Center in Torrance, CA; providing a copy of your repair invoice, and requesting reimbursement since your car is having the same problem as the cars covered by the LSC.

Good luck, it sounds like you will need it.

For reference, please see:
How to Replace the Inverter Coolant Pump | PriusChat
LSC A0N - HV (Inverter) Water Pump; Dealer Letter and Technical Instructions | PriusChat

 

Be aware the older the coolant is the less you will see movement. It gets contaminated with aluminum corrosion
which is very abrasive and I suspect eventually destroys the pump.
I changed my coolant at 35,000 miles as I noticed it did not have as strong a turbulence as when new and had white dust in the cap. I took some out and it looked bad. New coolant improved turbulence plus I used this product in the tank too:


Red Line Synthetic Oil - WaterWetter® Coolant Additives - WaterWetter®


Now 20,000 miles later fluid looks clean, no more white dust, and good turbulence.

Btw, if you like what we are doing to help you there's a LIKE button on the bottom right of our posts. Click the blue word like.

 

Great! That dealer sucks. You scare them as your pretty competent with the scangauge. They don't like that.

Those new MG numbers look right on the money. Maybe a tiny bit higher than what I see in my car but I have fresh atf on board.
Which leads me to one more thing:
Since you have stressed out the trans I suggest if you end up keeping it to have the trans fluid replaced. You cooked it pretty good. But not by those dummies. Its very very easy to do and any indy can handle it. I have done mine twice so far in the driveway. Just open bolt...dump fluid...close that bolt (make sure you have that bolt end cleaned as it has a magnet on it). Open fill bolt and pump in 4 quarts of Toyota WS Fluid. Around $10 a quart at the dealer parts counter.

I change my trans fluid and Inverter coolant every 35,000 miles. The Inverter coolant change is wicked easy. Alot of us on here do. Its cheap. And will help get the car to 200K + miles with no big drama.