How to make the HV battery fan to run all the time?

The controller for the fan is located in the black plastic outlet duct mounted to the passenger side of the HV battery.

 

Also, there should be a related code.

 

No codes… unless the battery is allowed to reach over 125f… in which a code for high battery temp is set…
Thanks

 

I believe that is the fan rectifier, and seems to work correctly as the app is able to vary the fan speed. Issue is … the battery temp sensors are reporting the temperature… but something is failing to turn on the fan. App will do all this…thus implying all parts are working. Appears the ecu may have incorrect or no temperature kick on setting in place. I will however take a closer look at that outlet duct component you are referring to.

Thank You
Frank

 

There's nothing to rectify: the power source is already DC and the fan motor runs on DC.

The controller in the duct is not much more than a nice heat-sinked transistor, able to take the pulse-width-modulated SI speed signal from the ECU and drive the fan motor with it. Indeed, your ability to alter the fan
speed manually confirms it is fine.

What does the Data List show as the selected fan speed, at various battery temperatures?

That would imply your ECU is running different firmware than everybody else's ECU. Seems a stretch.

 

Unfortunately, there are no fan icon in hybrid assistant on the Prime so you can't adjust its speed.

 

My hybrid assistant app shows fan speed, and "A" in the fan symbol which designates the app auto control the fan...
Try rotating your phone to display in wide screen... I believe the fan control will show then...

Thanks

 

Thanks for the schematic! This is helpful...
Today I attempted a ecu reset by removing the ground cable from the 12v battery for 5 minutes. This seemed to clear the ecu as removing the 5amp 12v battery fuse did not clear anything.
Now I noticed that toyota ecu will control the fan ...speeds 1-3 ... around 100f fan is at speed 1, at 106f fan speed is at speed 2, at 116f fan went up to speed 3. This is better...but not good enough as the center hv battery bank was red at 121f ...the 3 banks were as follows. 117f, 121f, 116f.
Once I launch and enable Auto fan control on hybrid assist app... fan speed goes to speed 6 (Maximum) and battery temps begin to drop toward 102f over a 20 min period... this is ideally were the battery accepts the maximum 25 amps regenerative or engine charging rate.
I wish I could see what the toyota fan controller speed set points are... suspect only toyota service center can do such...
Gonna may a youtune video soon discussing this issue...
Thanks

Frank

 

Now I see the problem. Because your APP shows it as being RED, you feel it's too high?
These cars, sitting in the summer sun, get higher than 125 inside. I don't think 125 on the HV battery is a crisis. The battery does have its own Toyota low and high temp values that will cut back on current to protect the battery. Why not let it do its thing?

 

When the HV battery is that hot you lose HP from it and the ICE is used more, wasting gas, so if you lower the temp of HV battery then you will get more assistance from it and use less gas.

Make sense?

 

Azusa, as proven by the majority of your posts, you wouldn't know sense if it bit you in the face.

 

Yea thats what an old person would say when they get offended.

Not my problem you didnt know any better.

 

Not fur nothing - I'm just guessin.
Have you tried either
disconnecting hybrid assiant or the adapter? The extra app control might be monkeyin with the cars normal fan controller.

I've had pretty good results using my old mini Elm and the newer version of hybrid assistant, dr prius and car scanner, but each gen has different PIDs controlling diff sensors. And a lot of time what works in one Prius doesn't always work in another Prius or while using a different adapter.

 

The same repair manuals that the Toyota Service Centers look in to see what settings they are able to change with Techstream, we are also able to look in, and "fan controller speed setpoints" aren't there.

Lots and lots of setpoints in the car are just hardcoded in the firmware. You can change the auto headlight turnoff timer in Techstream, but not the intake valve timing setpoints, for example.

It appears to be the same with the battery fan speeds. You can override the ECU's choices with something like Hybrid Assistant (for as long as Hybrid Assistant is plugged in and actively doing that), but changing the ECU's setpoints does not seem to be a thing.

Without reflashing the firmware, I mean. Of course in the tuner community people do all kinds of things by modifying the firmware and reflashing it.

 

Cordless leaf blowers have gotten quite inexpensive over the last few years. With a bit of duct tape and study of Apollo 13, you could run some air through it at 180mph for a few minutes before you start a hot car.

 

This is coming from a guy that installed a little computer fan in his battery. How's that working out? You have no clue about airflow, thermal mass and cooling. You just keep spouting BS. If your battery was hot enough to cause problems, you would have to sit in the car for 30 minutes or more with the fan running at full speed to see a difference in battery temp.

I take dumps that show evidence of having more intelligence than 99% of your posts.

 

Any thoughts on hard wire and toggle switch to manually control the fan?

Posted via the PriusChat mobile app.

 

That time you forget to toggle the fan on will be worse for the battery than just letting the ECU run it the way it's programmed to.

 

The only way I've gotten mine to run is with my XTool D7 Scanner.

In my wife's 2017 Prius LE, you can hear that fan when it's running but in my 2021 Prius AWD, it's much quieter....not sure if Toyota upgraded the blower with a quieter one or if it's because my batteries are Li-Ion (Lithium-Ion) while hers are NiMH (Nickel-Metal Hydride). And even though my car weighs almost 200-pounds more, always gets better MPGs.

 

@TMR-JWAP

So....what you are saying is all your intelligence is going down the sh!tter?