2010 Prius Check Hybrid System message

I'm not saying this is a confirmed information but for me it would make no sense to waste energy on a pump that doesn't need to be running since electronics in the inverter can operate in a high range of temperatures.
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Operating temperature - Wikipedia, the free encyclopedia
It should be ok at least in temperatures in between 0 ° to 70 °C

 

i wonder how many people have replaced perfectly good pumps because of my bad advice.

 

At least your advice keeps the aftermarket parts suppliers in business .

 

Are you sure it was bad advice? Don't admit to errors you didn't make! My inverter pump seems to run all the time the car is "READY," even when nothing is hot. Whether it speeds up when temperatures in the inverter increase, I don't know. That would seem reasonable.

 

A brand new battery at 11.93 is defective or return or sitting around way too long. A new conventional battery should be around 12.6, an AGM 12.7~12.8.

 

I checked my 2010, 3rd gen Prius and the pump seems to be working all the time. The fluid in the reservoir was moving a bit and the pipes vibrating a bit too.
Looks like you were right. I did found for sure that 1st and 2nd had the pump running all the time but didn't find anything about 3rd gen. The misleading thing is that the technical specs say the speed of the pump is regulated by the on board computer so the pump runs all the time at minimum and speeds up when needed.
This absolutely makes no sense to me. Toyota uses there own developed Insulated-gate bipolar transistor with work temperatures from -20 degrees C to 150 degrees C.
So since the ECU controls the pump speed it has to do on some basis and I would guess it's temperature. If they measure temperature, have control over the pump speed and the working temperature of the transistors is so high then for me at least there is absolutely no reason to have the pump running all the time.

I also found something very important while researching this!
Turns out the 12V battery is charged by the inverter from the traction battery so the petrol engine does not need to be running to charge the 12V battery.

 

the only thing i'm sure of is, i'm not sure of anything.

 

How many miles on her?

It sounds like the fluid is not moving or vibration in the line, but Do you hear the pump turning on? A blown fuse possibly?

If you are going to remove the pump, might as well do the coolant change. A good video posted here on PC for doing it.

Is the coolant level normal, or have you seen the level drop? Ever have any damage to the front of the car where the pump may have been impacted?

 

what is the battery voltage, stone cold, now that you've charged it?

 

By normal fuses, you mean under the hood in the fuse box and all fuses looked good? From humming in the front of the car, probably means the pump, was trying to run ( pump is located between the drivers headlight and the just below the inverter).

You might have a problem with the impeller in the pump if there is no fluid movement seen on the reservoir. If at the full mark, I would not suspect that the pump got starved or had air suck into it going around a sharp turn causing the pump to momentarily run dry.

Not many problems reported with the gen III inverter pump that I remember, so I am curious what you find as I am currently at 138 k and going to change my coolant out in a couple of weeks at 140 k. Might expand my plan. Keep us posted.

 

Fuse box location is in PDF manual on 485 page, 462 on paper manual. Fuse box layout is on 488 in PDF.

There is no specific fuse marked as "inverter pump" so I'm not sure if one those is the right one:
5 ENG W/P 30A Cooling system
9 IGCT 30A PCU, IGCT NO.2, IGCT NO.3
10 DC/DC-S 5A Inverter and converter
25 PCU 10A Inverter and converter
26 IGCT NO.2 10A Hybrid system, parking control system, power windows, inverter and converter
34 IGCT NO.3 10A Cooling system

 

Before doing anything disconnect the 12V and the traction battery (the orange safety plug) just to be safe. You don't want to touch something by accident and have 200V on your hands

 

congrats!

 

To-do item done: it works great. I'll definitely recommend, with the caveat that they face a counterfeiting challenge too; the sure way to avoid that is to buy from their web store, even if something else looks like the same product with a fabulous price.

-Chap

 

Hi - I am having the same 'Check Hybrid System Warning'. I replaced the battery about a year or so ago. We use this as our primary vehicle, so it should stay charged. What might be causing this message? Thanks!