Water Pump

How did you come by that, and where on the engine does it go? Do you have any other pics of it? In place?

I'm sure I haven't seen it in the US parts diagrams....

Edit: ah, this post. The plot thickens.

Did you ever take the hose off to look at the gray thing more closely? What does it appear to do / be?

Goes on the cylinder head with a gasket, doesn't it? Exactly the same as 16331 in this post on your other thread, right? Except for the gray doohickey.

Too many threads....

 

I suspect it's a thermostat or a temperature sensor or both I did not get a closer look as I did not remove it again two weeks ago my car ran fine I swapped the damper took the engine out put it back in drove it around for 2 weeks no problems suddenly my pump failed and now I have two other pumps that are failing or have failed

 

Identified it in the other thread; it's a version of 16331 OUTLET, WATER used in Europe and Japan but not North America (so far).

 

I got the engine from a company I. Fresno ca jdm engine

 

Ok here are some pics. We did not agree but we are friends now as you can see. The tiny hole does allow for follow going around the edges but I think the hole should be bigger.

 

chap! Is this Toyota subscription also available for foreigners in Africa, or it's just restricted to North America?

 

In the wiki page that Elektroingenieur put together, under the heading "Toyota Subscription Databases", there are URLs for the North American, European, and Australian TIS web sites. I don't know if those are the only ones there are.

Elektroingenieur also mentioned, under the "CD-ROM/DVD-ROM" heading, Toyota Service Information (Global Service Information Center), which apparently produces discs for other countries, but these might not be offered for sale except to dealers.

Maybe @Elektroingenieur would have some way to learn more about what the exact story in Nigeria is.

It's possible that Toyota's practices may be influenced by which countries have strong copyright protections, and by which countries have right-to-repair laws.

 

Have you checked the sensors? Perhaps one is bad and giving the wrong reading.
It could be telling the ecu that the coolant is HOT so it's running the pump at full speed to cool
the engine coolant. I don't know if running the pump at full speed, even with coolant flowing, would
make it over heat. Maybe too much voltage too long?

 

I have a feeling you're replying to johnnychimpo's burning-up-water-pump question, which has its own thread, probably the better place for that discussion.

This is more of a generic thread about how the Gen 3 water pump works; johnnychimpo's thread is a good place for the nitty-gritty of what happens when a Gen 3 has a Gen 4 engine fitted into it and the Gen 4 engine was built for a different market region and that market region includes different mystery parts in the cooling system that aren't explained in the North American manuals and the mystery parts are kept in the cooling system (with or without extra-big holes punched through them). So that's kind of a specialized topic....

 

How would you spoof that signal? And how do you think the system will respond by just installing a thermostatic relay into the circuitry humming it seems like it would just turn it on when the system reaches 180 and then turn it off when I reached 160 or how are you gonna send it your thoughts?

 

When I wrote that (4 March 2021), I wasn't sure when I would get around to doing that, so just wrote "for another day".

But I got around to it a couple weeks later, so to see how it was done, you can read that post.

Well, two things. Having the water pump ever turned off (say below 160) doesn't sound like a good idea. It sounds more like something you would do for cooling fans or the like. I don't think you ever want the engine to be running with no circulation of the coolant. That would just mean certain hot spots get hotter and other spots stay cooler and the temp sensors only know the temp of the coolant sitting right there, and the engine gets weird stresses from more expansion in hot spots than cool ones.

In fact, that was the whole reason when I did that experiment to see how the ECM responded to the pump not running, I did not do it by stopping the pump. The whole point of the spoofing was to see what the ECM would do when it thought the pump wasn't running, but really keep the pump running so the engine wasn't in danger.

So if you really wanted to do some bang-on, bang-off relay thing, you'd certainly want it to bang-on whenever the engine runs. Also when the engine is stopped but the cabin heater is in use.

But it would seem a shame to take a variable-speed pump and an ECM that knows how to control it, and just turn it into some bang-on, bang-off deal.

 

You seem to be on top of this issue and I hope your still around. Maybe you can help me ? I installed a new pump and still get dtc p261b . I powered the main and the pump works fine but when I start the car I get a check engine light and then the pump can’t be jumped anymore. Its like the ECU is telling it to not to accept current. When the car is off I can power the pump again by jumping it. So I know it’s not a bad pump. Do you think it’s the ecu? Any thoughts ??

 

I see your point but am running out of ideas. I’m sure a relay would probably keep the pump on as the temps would rise but what would be the drawback? Would it wear out the pump faster? I know I’ll get a check engine light but what else can I do? I don’t think it’s the temp sensor or it would throw a code ? What else could it be ? My ecu? I checked all the wires for continuity no issue. Ground is good. Large blue is good . Thin green has 12-14 volts but the thin blue shows .03 volts. Ecu ?

 

Making those measurements is a good start. What are you using to measure with? Also, do you have Techstream available?

This might sound kind of homework-y, but it's a really effective technique I use myself to understand stuff better. How about if you go back over posts 36 through 39 in this thread, and then write an explanation in your own words of the four wire connections at the water pump:

• the purpose and expected behavior of each one
• how you could measure or otherwise get visibility on what each one is doing
• what you would normally expect to measure there
• what might be the causes if you measure something different
• how you could work through those causes to eliminate the ones that aren't

It's probably worthwhile to pick a single thread here on PriusChat and keep your progress there in one place, rather than spreading it over a bunch of different threads. It might even be worth starting one thread just for the purpose ... including a link back here for older context, but restating the basics in your story to this point, and having one place for taking it further.

Also, when reporting a measurement on any of those circuits, it can be helpful to say precisely where and how you measured it (post 37 upthread gives an idea of how that can matter).

 

Gen 4 Prius uses the same pump? shame on that.

 

It's been reported that the Gen 3 and Gen 4 pumps have different part numbers, but whatever differences there are seem to be subtle.

 

Seems like they still used the plastic impeller that causes the pump to fail. Bad move.

 

My impeller had 270,000 and had not cracked or swelled....

 

So did you put it back then?