Hello, I hope someone can help me out here. Here's my situation: Bought a 2007 Prius a few weeks ago, and have been loving it. However, the last couple days, I've been bombarded with incessant "cannot change to ev mode" beep and message on the main display. After scouring other forums, I learned that EV mode is a pretty common mod that people do, and I'm aware of the reasons that EV mode wouldn't be able to engage. However, there's no visible sign that this mod has been done on my car (certainly no switch has been installed), nor is this a feature that I want to engage. If anyone can think of ways that I might be able to disengage EV mode so that I stop getting this obnoxious beep all the time, I'd really appreciate it. A bit more specific info below: -It happened a couple times in the first couple weeks of owning the car, but not nearly enough to cause any bother or concerns. -This week, it's gotten to the point that on certain drives, it will beep at me and display the message over 5 times per minute, for over 30 minutes. -I turned off the display when it was really bothering me last night. This seemed to solve the problem. -I turned the display off again this afternoon when it started up again, but this did not solve the problem this time. In this case it continued to give me the beep and message, only using the top part of the display without turning the rest of display on. -It seems like it happens more when going over bumps, but this may just be coincidence -I've tried engaging other switches that I've read on various forums are sometimes used for the mod when choosing not to install a separate switch (high beams, cruise control), but to no avail. I'd really appreciate any suggestions or thoughts. This is driving me crazy. If I can't get it to stop, I'll probably try the dealership, but would rather avoid that.
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.
Thank you all! Jerry, a video would be greatly appreciated when you have time, but no rush. I imagine I can also find something by searching online. Any other suggestions on things I could try before removing the dash? Perhaps there's another existing switch that people coomonly use in the mod that I may be able to trigger to turn off ev mode?
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.
Jerry, thanks for the video, and glad to hear everything went well for your wife! Update: I followed everyone's advice and determined that in fact a previous owner had installed the switch. Either the Coastal Tech one, or something very similar. It was very easy to remove (probably even easier than installing it was). Based on how easily the wire came out (the one that was jammed into the harness), I'm thinking it may have been too loose, which is what was causing it to malfunction. I haven't actually driven the car yet since removing the wiring, but I'm confident that it will solve my problem. How could it not? Thank you everyone for your help! I really appreciate this!!!
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.
