Heating up of Toyota Prius Wagon third generation

I completely agree with you. However, what’s strange is that when I removed the original Inventer water pump from the car and compared it with the new one, I tested both using a 12-volt battery and they both ran. So, I took out the original and installed the aftermarket one. Before installing it, I tested it and heard it running, so I assume it works.

By the way, I’m referring to the Inventer water pump from the heat pump system of the hybrid system, not the water pump of the petrol engine.

 

Good evening everyone,

I would like to provide you with an update regarding the overheating issue of the hybrid system. I have since installed an original water pump. I also had an electrician carry out electrical measurements. The results showed that both the 12-volt power supply and the signal from the ECU are properly reaching the water pump connector.

It’s important to mention that this vehicle has two ECUs: one for the petrol engine, and the other for the hybrid system, which is integrated into the inverter itself.

However, I still haven’t been able to verify whether the feedback signal from the pump to the ECU is functioning correctly.

I’ve added a link to a video in which I clearly explain how the problem occurs. When I drive on the highway at high RPMs, the issue comes back: the dashboard displays an overheating warning. After that, the car loses power and the engine speed drops.
At that moment, the engine warning light (engine management light) turns on. At the same time, both fans of the main radiator start running at full speed.

In other words, I haven’t made any progress and I’m still dealing with the same issue.
I’m now considering replacing the inverter.

 

Dear rjparker,

A whining (howling or humming) sound during acceleration in a Toyota Hybrid is often completely normal. Here’s why:

Why do you hear that sound?

Toyota Hybrid models, such as the Prius, use a CVT (Continuously Variable Transmission). This allows the engine to run at a constant RPM during acceleration, which improves fuel efficiency. As a result, it may sound like the engine is “whining” or “revving” when you press the accelerator, especially during strong acceleration.

When is it normal?

During rapid acceleration (e.g. merging onto the highway).

When driving uphill or under heavy load.

When the engine has not yet reached full operating temperature.

 

Good afternoon,

Yes, the problem has finally been resolved. I feel that true craftsmanship is hard to find these days. I went to the dealership and saw several mechanics, but in the end, I went to another garage. There, they simply followed the coolant lines using air pressure and discovered that the coolant wasn’t circulating in the hybrid system because the hybrid radiator was completely clogged.

The mechanic ordered a new radiator for me for €110. He charged €150 for the installation and labor. With that, the problem was completely solved.

The dealership charges €180 per hour. They start a new diagnostic process each time, with a new strategy. Before you know it, you're paying €2,000 or €3,000 to solve a relatively small issue.

I'm now going to visit the dealer and confront them. After they saw that there was oil in the reservoir, they told me they would clean the entire hybrid system circuit. If they had truly done that properly, they should have found the blocked radiator. In my opinion, they didn’t do that. It feels like no proper cleaning was actually carried out.

In any case, the issue is now resolved. I sincerely thank all of you for thinking along with me and sharing your advice. I wish you a pleasant day, a healthy year, and cars without problems!

 

No, sorry,
I honestly have no idea. For me, it was simply a matter of the radiator being clogged — replacing it with a new one and that was it. That was the quickest solution for me, and I was satisfied with it. I didn’t investigate any further.

 

Just a small update. Since I replaced the radiator, the issue of electric shocks when turning off and stepping out of the car has also disappeared. I suspect that the lack of coolant circulation in the system may have caused a magnetic field or electrical charge, which led to me receiving an electric shock when exiting the vehicle. I just wanted to add this as an extra update.