EVMode Option for Prius 2004-2009: Will install void Platinum Warranty?

1. Dont buy the one from juicedhybrid. Its a copy of the one from coastal and they even stole the picture from coastal. As far as I know this is still the case. I would suggest either spending a little more and get the OEM look with the real EV button or installing a button from radioshack to get the job done. There is no delay in using the OEM button or a button you get from radioshack. You can get the OEM button from World's Largest Prius-dedicated Accessory Shop :: Sigma Automotive I have no affiliation with that site.

2. It can help improve your MPG but only if used correctly. There are many posts here and on cleanmpg.com on its proper use.

3. The car still keeps the battery in the safety limits even when you use the EV button.

Over all the button is really only helpful if you have you car converted to a plug in where you can actually benefit from keeping the car in EV only mode.

 

Helpful vs. Efficient are different in my book. As far as efficiency, the other place it would be helpful (other than being a PHEV conversion) would be if you do a short trip around a parking lot. So park infront of store A, then you want to go get gas in the same plaza, then pickup something else at store B in the same lot. All those are perfect for EV.

Now I use my EV button differently. I use it as the above but also just for consideration. I am constantly leaving my house in the middle of night. So I keep it in EV mode until I leave the immediate neighbourhood. This lowers my MPG, but it doesnt disturb the neighbours. I would like to think that my neighbour with the diesel truck would do the same if he could

 

Coastal = "Coastal Tech": Electric Only Mode

Their part uses the cruise control I believe to activate it. I much prefer a button.

You can get the OEM button which fits with no modification here: Toyota Prius 2004 ~ 2009 NHW20 Interior Accessories :: Sigma Automotive
(Look half way down the page for "EV Button")

You will have to completely disassemble the dash to run a wire correctly from the driver side to the passenger side hybrid ECU which is below the glovebox on the right.

Being a girl has nothing to do with it. You can do it in a couple hours if you take your time. If you are good, you could do it in 20 minutes.

 

And you will more than likely void your hybrid drivetrain and traction battery warranty. Overuse of the button or misuse is an issue and will wreck the battery. But given the amount of people with battery failures before 100k miles (very very very few), the warranty is pointless anyways.

Remember that the Toyota bean counters are very smart. You don't get to be #1 being stupid. They know they can offer 100k mile warranties because the batteries will not die until after that period. If they did, then they wouldnt make money. If your battery hasnt died yet, it goes to reason that it will not until well after the warranty expires. And even then you can pick up a used one or reconditioned one off of ebay really cheaply.

 

Coastal Electronics is a guy who lives in Indialantic FL who was
producing various add-ons for the Prius, and may still be but we
don't hear a lot about him these days. His notoriety comes from
horrendous, or maybe that's just nonexistent, customer support.
His "EV mode" controller is a hack that tries to draw enough
power off the cruise-control lead to fire a grounding transistor
to the EV lead. Here's some detail on what's in the widget:
http://techno-fandom.org/~hobbit/cars/coastEV.jpg
The community has found it rather prone to unreliable operation.
.
Whether you use something like this or roll your own [pdf link]
you still have to add a pin to the ECU plug and arrange to
momentarily toggle it to ground to go into [and back out of]
EV mode. It's pretty simple, and the benefit of a direct switch
is that it toggles *exactly* when you want and doesn't have any
side-effects like the high-beam-switch hack would -- yet another
option on control. Once you get familiar with how it kills the
engine, you really want instant action because in proper usage,
however infrequent, it's going to function just like taking your
foot off the go-pedal does in stage-4 operation.
.
Plenty o' reading material, and whether you use it a whole lot
or not, installation is fun and gets you familiar with digging
around in the ECU wiring -- never a bad thing.
.
Second on the disrecommendation for Juiced, by the way.
.
_H*

 

Another vote against JuicedHybrid. And another in favor of the home-grown version. Here is my installation writeup.

I disagree somewhat with Evan's position about how little it helps fuel economy. I do agree it can hurt FE if used wrong, and most initially seem to want to use it wrong. It's counterintuitive, but it should not be used for extended electric-only propulsion. But I am convinced that with proper use and under the right conditions -- which admittedly not all drivers will have -- it can improve FE significantly. See this for more.

And while I'm being disagreeable, I also disagree with 2k1's assertion that it will wreck the battery -- potential warranty denials aside. The car is very protective of the battery and automatically shuts down EV mode in a variety of conditions that could stress the battery. Overseas versions of the 2004-2009 Prius and the 2010 North American model have a factory EV button. I doubt Toyota would have included it if it was likely to damage the battery.

That won't stop Toyota from trying to deny a warranty claim, as others suggest. Here is the link describing Naterprius' experience. Install at your own risk.

 

If you purchased your Prius (and warranty) recently, you may be able to cancel your extended warranty purchase. (If you want to get an extended warranty, you can buy it ANYTIME until JUST before your normal warranty expires.)