Yesterday I decided to select EV mode while moving along at only 9 MPH. A screen message was issued stating that the car was at too excessive a speed. The EV battery showed a full charge (all ticks were visible). Maybe the fact that I had the heater on and the heater fan blowing had something to do with it. The headlights were also on. Is something wrong with my EV function? Jim
There are many other posts about this issue, so the simple and quick answer is no, there is nothing wrong with your EV mode; it seems to be finicky. I have experienced similar outcome when trying to use it as well. I do find that the car likes to be warmed up before switching over.
Was the car warmed up completely? Were your pressing on the throttle too much? i.e. TPS voltage was too high at the very instant you tried to engage EV mode. If I am going to engage EV mode on my 2005 I make sure I lift off the throttle completely before I try to engage. EV mode is finicky on my car. I think that is a good thing though because most of the time people will use it in the wrong way and get worse MPG than if they never used EV mode.
IT happened to me a couple of times and I learned that by stopping the car and then moving back forward it work just fine. It might be a glitch or it just might be that it is too sensitive. Cheers W3Bconsultor
I am also trying to figure out the EV mode. I have found that it definitely won't work when I first start the car. But I haven't found that I've been able to use it for any length of time at all. Even when I stop the car, then switch it on, it goes off at just 9 or 10 mph. I don't get it at all.
Prius needs at least 158F coolant temperature to see 25 mph EV mode speed limit. EV mode speed Ken@Japan