Please tell me, what should the ECU data flow and EGR be like?

You can see the flow in HG in Toyoda software.

 

Where did you get the information from that you wrote in your post?

At idle, the EGR is fully closed on the Prius.

 

The information that you found on Google is not correct.

If you are looking at live data for the EGR valve when the engine is idling, you will not see any change in the data because the EGR stays closed at idle.

What are you trying to do with the EGR?

 

You'll get that taken care of at some point

 

I have no idea what your scan tool is showing for the EGR data. Maybe someone else can help you.

 

That scan tool seems not to even know what kind of a car it is talking to. A gen 3 Prius does not report EGR information in that way.

Perhaps there is some way to get that tool to show the result of the mode 6 noncontinuous monitor (module ID 0x31 test ID 0xBD) that the Prius uses. It should look like examples you see in this thread.

 

You’ve got 3 threads going now, essentially the same topic. You’ve got a recently acquired 3rd gen, it’s got over 200k miles:

Help Engine shaking and abnormal noise are not EGR problems | PriusChat

Next post you disclose code P0301.

I’d start checking for head gasket failure, and cleaning EGR system, in that order. More info in my signature (on a phone turn it landscape to see signatures).

 

The scan tool that he is using is a very basic, generic, inexpensive one that I did an online search to get some information about. I could not find who the manufacturer is. It is a generic scanner made in China.

 

All universal scanners are made in China.

 

Universally bi-directional capability and all of that fancy stuff has not fully taken hold and the scanner market yet so therefore you still have these cheap glorified reader only can do nothing else type of devices that are like 20 to $34 or something you just want to get a cut above that to like an ap200 there are other things like the ap200 now I don't have all the names that can bleed the brakes and set the linear valve offset this is not rocket science I think before years ago this is the kind of stuff that you were stuck into subscriptions to be able to make happen or you worked at the dealership and had their equipment now we've zoomed past that most of this software is pretty much free it just has to be harvested and exploited I'm not buying that Toyota or Chevrolet does anything too fancy with their software once it gets out in the wild it's just out there who cares apparently they do a little bit or something because they keep making nonsensical changes to the nothingness. Just to keep people buying which is predominantly shops people that are going to work on up to four or five year old junk all the stuff that's failing they need that to make their money thank God I don't.

 

Lots and lots of scan tools, even cheap ones, should be able to do Mode 6 queries, which is a standard OBD-II thing.

The one the OP is using seems to be more wackadoodle than most.

 

Yes even my Iinova 3100 we'll get some basic freeze frame data usually not hella useful but it does do it and it reads codes that it can identify puts them on the screen but doesn't know anything about it just has the number but I would expect that. But now we're so far past that put another $25 with the money you're spending and you can bleed the brakes and set the linear valve and a few other things for like 68 bucks I mean you got to be kidding a lot of these things I think people find in the trunk and Dad's old toolbox and stuff like that

 

The data that your scanner is showing about the EGR valve is not meaningful.

I will ask again. What are you trying to do with the EGR valve?

If you just want to see if it opens, take a look at post #12.

If you want to check if the EGR valve is not closed and it is causing the engine to run rough at idle, then remove one of the two screws on the pipe downstream of the valve. Insert a putty knife to block any possible flow. If you search on YouTube, you will find a video about this.