Cannot change to EV mode but I don't have ev mod

I'd look at the guide on how to install the switch and follow the steps to see if you can trace any previous installation. It's possible that someone installed it and now the old installation is suffering from the occasional short-circuit from wire chafing or faulty switch. Especially since you're saying it happens when you go over a bump. You'll soon see that the way the two circuits are separated and the way you have to wire everything that it's very unlikely for this to be occuring on an unmodified vehicle.

 

I was thinking about the same as @SRQ. It may be that the previous owner put in an EV button and only removed the button, but not the wires. It would connect to the ECU that's behind the glove compartment. If that's it, there would be a wire scabbed into its connector and not in a harness. You do have to take apart quite a bit of the dash to get there. I can post a link to a video for taking apart the dash if you want to pursue that line of investigation. But I'm about to leave and won't have much internet access for a couple days.

 

mine was plugged into a block connector behind the glove box. coastal company. just a jumper wire or some such. but that was the cruise control stalk.

 

Hopefully here isn't a Hymotion system hiding in the hatch area in the spare tire area.
If there is, there should be a bypass plug that can be inserted.

 

I'm back. Wife had an angiogram yesterday and it went way better and faster than anticipated. She even came home same day. Yippee!

So,
Here's the video I used for reference when I needed to clean my wife's combo meter. So it goes way beyond what you would need, so just follow it till you get the ECU exposed. It's not hard at all if you follow the sequence.

 

Sorry for bringing this thread back to life...

I am having the same issue. I purchased this car a couple weeks ago, and it frequently flashes the message to the screen. I wasn’t too concerned at first, it was just annoying. However, this morning I tried to put the car in Ready Mode and all of the dash lights lit up including the “red triangle of death.” I unplugged the 12V battery, plugged it back in and now the car is running just fine again, but still occasionally has the “Cannot change to EV mode now” message. How concerned should I be?

 

you need to read those trouble codes, next time all the lights come on, before unplugging the 12v.

speaking of which, have you tested it?

 

You should be concerned about the codes and get them investigated as @bisco advised.

The inability to put a car not really meant to be driven in EV into EV mode is simply the car protecting the battery because the battery doesn't have enough charge for that kind of abuse. I get the same on my wife's 2015 Prius if I want to move it out of the garage w/o warming up the ICE when the traction battery is below a certain level.

It may be that the battery level is related to the codes you've been clearing without reading. They are not a nuisance. They are a warning.

 

These two conditions can be coincidental, but it doesn't really matter in this case.

The car is reporting that the hybrid battery is starting to fail. This is serious, the car is probably going to need a new hybrid battery. At a minimum it should be checked over by somebody who knows hybrids to confirm.

The "cannot change to EV" is just an annoying nuisance, it doesn't change anything for the first problem, but it may come up more often because the computer has the battery flagged as failed.

Disconnecting the 12v clears the flag and lets you start the loop again but that's all it does. Car needs help.

 

Hmmm. I just saw something I didn't catch before.

You just bought it and this happens almost right away? Odds are, it was doing that before you bought it, the seller knew it, and they were resetting the codes so they could sell their problem to someone else.

 

Amazing no one posts the mileage on there car.

Hybrid Battery probably has a ground fault. You got stuck just like jerry said. We see this all the time.