Number of inverter pumps?

Ok, I take your point, in case the OP personally had no idea that the reason for an inverter pump is to pump coolant to cool the inverter.

But the first post also mentions what was said by a mechanic at a local garage about the number of pumps appearing to be there. And it seems like the mechanic had enough of an inkling to have counted all the things that look like pumps connected to coolant hoses, and not the other thing that looks like a pump connected to steel brake lines.

So it still seems like the space for possible legitimate confusion, which I took the post to be about, is still really because of the number of similar-looking pumps that are attached to the same sort of hose and look to be for pumping the same kind of stuff.

-Chap

 

Yeah: two coolant circuits, one for the engine, one for the inverter, and one coolant pump for each.

The term used for describing both in the Repair Manual is "water pump". Attached are Repair Manual excerpts for replacement of both.

 

But, but, but, noooooo, haven't we been here before?

Two coolant circuits, one for the engine, one for the inverter.

One coolant pump for the inverter circuit.

two coolant pumps (Gen 1), three pumps (Gen 2), one pump (Gen 3 onward). Gen 4 I can't speak to for sure, but I'd guess it's two, like Gen 1 and Gen 3. The thermos bottle with its dedicated pump was just a Gen 2 thing.

Refer to post 37 of this thread.

-Chap

 

Oh eff, thought this was third gen. @ChapmanF , I'm keeping you as busy a cat in a room full of rocking chairs.

 

it has been one of the more confusing threads.

 

See if I can redeem myself: attached are four second gen repair manual excerpts, for coolant pump removal/install: engine, inverter, heater and the heat storage bottle.

 

The fourth-generation Prius has just one inverter water pump and one engine water pump, and replacing the latter requires removing the engine assembly with transaxle. I hope it lasts.

 

Does the fourth gen not heat the cabin with coolant when the engine is stopped? Or does it just use the engine water pump for that purpose?

-Chap

 

Hopefully this is an instance of the absurd over-removal recommended in the Repair Manual.

But yeah, sometimes they're not kidding, 3rd gen spark plug removal and the need to remove wipers and cowl, for example.

 

ouch, another strike against gen 4. poor pump reliability after warranty could be a nightmare for folks.

 

I believe it’s the latter. The Engine Water Pump Assembly is shown in the diagrams for the air conditioning system. Toyota writes in Course 752: Air Conditioning and Climate Control, “Some hybrids replace the conventional engine water pump with an electric engine water pump controlled by the ECU. In this case a separate electric heater water pump is not required.”

 

Huh. Maybe I'm mistaken about Gen 3 then. It certainly has the electric pump on the engine, but I thought it still also had the separate heater one. I'm not signed in to techinfo right now to make sure....

-Chap

 

For 2010 and 2015, New Car Features says, “The air conditioning amplifier assembly calculates the flow rate value required for the electric water pump in accordance with the engine coolant temperature and air mix damper opening degree and sends it to the ECM.”

I didn’t see any mention of a separate water pump for air conditioning there or in the Repair Manual, and the ECM is controlling it, so I assume “electric water pump” means the one attached to the engine.

 

Just for clarity: "air conditioning" in Toyota texts means any and all cabin ventilation, not just mechanical cooling, with the compressor and condenser.

 

Thanks, so I stand corrected:

Inverter circuit: one pump (all generations)

Engine circuit: two pumps (Gen 1), three pumps (Gen 2), one pump (Gen 3 onward).

-Chap

I've reported my posts 17 and 24 asking the mods to correct them.

 

Just one for invertor. Just got done changi g my bad abs acumulator/pump, so had all those coolant lines disconnected, and fluid wouldnt stop coming out even after draing the hot water heater.lol