Gen 3 Prius Battery Fan Operation

I've not seen any evidence of its operating speed being based on vehicle speed... But it does have relays and a complicated method of slowly speeding up that can be frustrating when trying to diagnose it.

 

If the fan is not working properly you should get an error code and a warning light... If you don't have that I wouldn't worry about it. You can independently monitor battery temps via Dr. Prius app using one of these: Hybrid battery diagnostic and repair tool for Toyota and Lexus

 

Same here. When the car is parked with the engine ON, (and AC On) the battery temperature rises, and the fan does not turn On unless you drive it above 25mph (i think). Thats when the barrery starts cooling off. (i have a thermometer to monitor the temperature). SOOOOO Toyota made a mistake or on purpose so we damage the batteries with heat etc.

The fan should turn On when the betteries heat up.
I would line to find a way to make the fan work without having to drive about...

 

Could either or both of you post some further details of your monitoring setup, and the logged data if any?

 

Get the Dr. Prius app and the proper obd-2 scanner. With the app in special features you can override the fan temperature to something much lower like 85 degrees. My 2012 Prius does the same thing where the fan does not really kick on until I’m driving above 25 mph, but if you put your ear up to in while stationary you can hear it pulling a little bit of air in but it’s very quiet.

 

this video goes into some detail. It is for an app called Hybrid Assistant, and explains temperature limits and efficiency.

 

I don't intend to be running an app in my phone in the background every time I drive. Is there a way to reprogram the car to set the fan temperature limits differently?

 

No

 

I did it through the Dr. Prius app “special features”. Also disabled the reverse beep and seatbelt beep. I set my fan to come on at 70 degrees.

 

That only works as long as Dr Prius is running and connected to the obd2.

 

When I’m connected, my fan runs constantly at usually the highest speed. But I noticed a difference after changing the setting last year and in the spring and fall time I can actually hear the fan running (without being connected) when before using Dr.Prius I’d only hear my fan kick on in the summer time. Also before changing that setting in the app, during the hot days in the summer the fan would turn on the highest setting for maybe 10 minutes during a long trip, now it stays consistently on during long trips (also without being connected).

 

Disabling the back up beep was the FIRST thing I did when I set up Techstream!
I have the xtool D8 now, and it sure seems easier and FASTER!

 

Parker? Can u help me here?

 

I would suspect high battery temps and an engine running when it should not be means a failing hv battery or a clogged blower wheel.

I watch engine coolant temp over battery temp. However I have rarely seen battery temp much over 100f.





Even though I live in an extremely hot environment and drive high speed highways most of the time, I have never used hybrid fan control strategies or had issues with the hv battery overheating. I am also on the IOS platform so can't use Hybrid Assistant.

My method is to park in a garage most of the time and run the ac at 75f constantly when driving. No pets in the car has kept the battery fan blower clean enough, I don't think I have ever heard the fan ramp up. Of course a v wagon has the intake duct under the rear seat which probably muffles it somewhat. The v also has higher capacity ac.

I have documented charging voltages around 13.4 vdc in Drive immediately going to 14.4 in Park. Why I am not sure but perhaps it has some effect on the battery fan. Doubtful and does not make good sense but the charging voltage change in Park is very repeatable.

 

Where did you get that digital temp display? I’d love to have that. Also being in South Mississippi/Alabama we have been in the 115 degree heat index this week. Also 80-90+% humidity. The highest my battery has ever got was 145 degrees. But usually I’m able to keep it around 95-105 running Dr Prius.

 

P10 link with unit shown before configuration. At this price it might be a close out on this model.

 

If I use the Dr Prius app to change the parameters can I then remove the dongle and it'll still have its effect on my settings?

 

See post #12 for the answer to your question.

Posted via the PriusChat mobile app.