Heating up of Toyota Prius Wagon third generation

That can be one of many problems including most likely a blown head gasket.

Best get it off the road, diagnosed and fixed or you will definitely be in for an engine

 

did you replace it with an oem pump from a dealer?

are there 12 volts at the pump connector?

 

1. You need to make sure the new inverter coolant pump is working properly.
2. You need to check and make sure your electronic engine coolant pump is also working properly.

I'm going to assuming you know where each coolant pump is located and which one you replaced and which reservoir you should be checking. Engine overheat is NOT logged in the OBD2 error logs, so if you don't monitor your engine operating temperature - you could be slowly destroying your engine - continuously running it HOT.

Hope this helps.........

 

What’s the miles?

 

This is the head gasket (item (1), highlighted in yellow):

It's sandwiched in the engine, between the cylinder head (23) and the engine block (22)

It's common for coolant to start leaking past the head gasket into combustion chambers, around your miles. I believe it to be due to carbon build-up in the EGR system, including the intake manifold (has EGR passages), the yellow highlighted components:

Symptoms of head gasket failure are:

1. Dropping coolant level in engine coolant reservoir
2. Engine shaking on cold-starts.

In my signature there's links related to head gasket failure, and EGR cleaning. On a phone you'll need to turn it landscape to see signatures.

 

Odds are good the inverter coolant pump issue is unrelated to the engine head gasket. However not seeing movement or rippling in the reservoir (driver's side) means it is not working.

The pump should always run in Ready mode.

Be sure you check the connector's power and ground. Power to chassis bypasses the pump's ground circuit which could be bad (unlikely).




The pump speed in controlled by a pulse train pwm input (pin 3) and the ecu receives a pulse train rpm (pin 2) feedback. These require an oscilloscope or scope meter to check properly although the wiring continuity can be verified with a standard ohm check.

My bet is the replacement inverter pump is bad. Almost guaranteed if it was aftermarket or used.

 

I would give odds that favor a problem with the pump itself or wiring damage ahead of the ECU itself. Not that an ECU problem is completely impossible, just quite rare in practice. (For some reason, there seems to be a strong human tendency to lean completely the other way and think "I wonder if it's the ECU?" whenever anything weird happens.)

 

A shock felt when exiting the car is nearly always a matter of static charge built up between your clothes and the seat or between the tires and the ground or both.

The car's high-voltage system is carefully isolated from all the body metal and from the low-voltage systems in the car. Any damage to that isolation fails a self-test the car constantly runs when READY, and will be reported as a P0AA6 code.

The system's goal is to have the traction battery never fully charged and never fully discharged, but rather hanging right around 60% ideally, sometimes as low as 40% or as high as 80%. The 'discharge' function you may have read about would be taking the remaining charge off the capacitors inside the inverter, after the battery has already been isolated when the car shuts down. But again, even if that were not happening, a lingering charge on those capacitors could give you a shock if you took the inverter cover off and shoved your hand in, but not out at the car body, unless with a serious physical failure of isolation between the two, generally reported with a P0AA6 code.

I offer a general caution around the phrase "based on my research", just because it's a phrase so many different people use with huge differences between the things they do that they call 'research', and some of those things can lead to pretty good answers and some not so much.

The more promising lines of research often start in the car's repair manuals:

Toyota Service Information and Where To Find It | PriusChat

 

If you are getting more than a typical static buildup shock I believe you would be the first to report such behavior.

Assuming the inverter coolant pump is not running, I suspect your shop will find one of the following in this order:

1. Bad pump receiving proper 12v and ground
2. Bad pump ground wire connection
3. Bad pump speed control wiring
4. Bad temperature thermistor although normal faults have specific codes
5. Bad Power Management ECU

The reason I think bad pump receiving proper 12v and ground is you said the power was checked. Hopefully the ground was checked at the closest pump connection.

It might be possible the pump is running but not moving enough coolant due to a defect.

 

The Scannerdanner channel is a respected creator in auto diagnostics but he is not a hybrid expert, a fact he mentions many times in the referenced video. He was not aware of the orange battery safety plug or even if a Prius has a thermostat.

In fact the gen3 water pump he is diagnosing is the engine water pump, not the inverter coolant pump. The schematics are different but the concepts are the same.

In his engine water pump case, he needed a pump. His engine water pump failure coded for failed control unlike your situation with the inverter pump.

Water pump impeller failure is a common problem which is usually best resolved with an oem pump, as aftermarket pumps are often defective out of the box.

 

When you are saying "heat pump", I assume that you are talking about the inverter cooling pump. If that is correct, then you are saying that the inverter cooling pump is not a Toyota OEM pump and that it is an aftermarket pump. Many aftermarket pumps do not work correctly. Most will work for about a year. Some will not work when you take it out of the box. This is what others are trying to tell you. The most probable reason you are still having problems with your car is that the new aftermarket pump you installed is not working because it was defective.