2010 Prius EV mode Hack

Funny - we in the US are limited to 25 MPH. So it is clearly a firmware thing....

 

I don't understand how people are getting reported speeds of like 25 MPH in EV mode. I have tried to SLOWLY accelerate from a stop but can almost never get past 9 MPH before the display indicated Excessive Speed and then drops out of EV mode. It is winter time now in northern OHIO but even when the car is fully up to temperature I get this same response. It is mildly disappointing. Overall I am very pleased with the car but I would like to be able to command it to run on EV only when I know I will be driving short little stop/go situations and really don't need the ICE on.

 

I have that 9mph thing too when its not warmed up, and it takes a long time to warm up. My guess is its too cold in Ohio to warm up when you want it. I would like to over ride. When I leave the house, there are a number of hills. If I could get it to 25mph ev then, I could get much better milage on short trips. When the car is warm it will use electric to go up, then recharge at the stop signs on down hills. I have no idea if there is any hack, as I can't go in eve (even to 9mph hills) when I leave the house.

 

I like the word "STEALTH"

 

The main reason you would be limited to 25 MpH is that your battery is cold. These kinds of batteries are much more efficient when warm. So when you start your Prius and it is cold, the car is limited to 25 mph on EV mode. If you drive several miles and the battery goes up to about 60 °C (the operating temperature) then you can hit 34 mph in EV mode (provided all other parameters are OK : battery charged, low acceleration...).

Gilles.

 

I have noticed that I can only get EV mode up to 25mph when my Scanguage reads 160F or more. But I have a feeling it is linked to something else besides engine coolant temperature because sometimes I can get it at 157F but not 162F. Maybe it is a battery temperature thing (which parallels engine coolant temperature), as others have suggested.

 

EV mode is available up to 25MPH via the ev mode button. The car, however will travel in EV up to 45mph (and yes, we are able to accelerate from 0 to 45 using EV only, although I have learned from experts on this site that it is not the most efficient use of battery) I don't know why toyota did not match the two speeds (ev button or regular ev) but that is what it is. If you are traveling between 45-112 mph and you release the gas pedal, the fuel will cut off, to me that is "Like EV" since you are not using gas.

 

Actually once the bar on the HSI goes past that center line the gas engine is on. While it is in the gray you are in electric. You dont need to push the EV button to be in electric. Just use that grey bar on the HSI to keep yourself from turning the gas on if thats what you want. I personally only use EV mode when Im moving around the driveway to prevent the warm up cycle.

 

I am just wondering if the EV mode is more of a gimmick than an actual useful tool. I can stay totally electric in eco mode, as I have seen posted here, as long as I don't try to accelerate too quickly.

What is the real difference between pressing the EV button and getting that nasty "you have exceeded..." message and just using eco and accelerating slower.

Is there something I am missing about the EV button? Some way to KEEP the car in electric mode until it hits 25 mph.

And . . . has anyone figured out a way to hack it to get higher than 25 mph. 28 would be nice, just to allow a few mph over the posted 25mph speed.

 

Once everything is warmed up, my UK gen3 can go to 31mph in EV mode.
It will also accelerate in EV mode untill I hit the PWR section of the HSI.

Seems like you guys have got some different firmware settings limiting you to 25mph?

 

Yep, for me it's 50km/h(31.0685596mph), it’s different in US. Wonder why…

 

I live at the top of long steep (~15% grade) hill. At the end of my commute in the evening, I burn a lot of gas to move the car up to the top of the hill. At the beginning of my commute the next morning, due to ICE warm-up, I also burn gas going down the hill.

Theoretically, EV mode could be used to delay the onset of the ICE warm up until the bottom of the hill. The the battery would be charging all the way down the hill due to regen-braking while gravity provides the motive power. Alas, it's very difficult (especially if one of my neighbors is behind me) to stay below the acceleration threshold while going downhill.

It would be nice if there were different EV mode thresholds depending on whether current was going in to or out of the battery, but this does not seem to be the case.

 

I am kicked out of EV at 10mph, very constantly.
Just wondering why? I am in USA, 2010, model II, got enough battery, other condition also seems fine.

 

Does not sound right to me. You might have some problem with car?

You better wait for some US users comments first. I really don't know how US model EV mode heat up is working..

 

The key is coolant temperature.
Please refer to post #18 and #36 on this thread.

Ken@Japan

 

Thanks guys really cool.

 

Speak for yourself.
I did not buy this car to be "GREEN." I bought it strictly to save money on fuel.

 

This is very true and only EV mode use that makes sense and has no MPG penalty. Too bad that one cannot use it when one really needs it (when the temp is under 60s' F).

I would prefer if EV started at low temp and would be a subject of low speed, slow acceleration, and SHORT trip limitations, rather that disabled in the first place.

 

You may want to build a ECT Spoofer to get you to S4.