Finally added the EV mod

[JimboK]

I've been reluctant to add an EV switch. I haven't seen many (any?) folks with the mod come out and say with certainty, "It saves me fuel." Therefore I couldn't justify spending the money or the time.

But as time goes on I become increasingly aware of this remarkable car's subtle -- and sometimes baffling -- nuances. What moved me to finally consider an EV switch is frustration with the ICE running between a string of 4 stoplights, most of which are usually red, in the middle of my commute. They're not far enough into the commute for the car to be in S4 operation. They're too far apart to "pedal-feather" EV without inciting hostility behind me, but too close to hit 35 MPH to get the ICE to shut off.

(For the uninitiated, 5 distinct warmup stages -- labeled S1, S2, S3a, S3b, & S4 -- have been described. See this paper for more. Though there may be some question as to the exact temperature and time thresholds where stage transitions occur, the behaviors are unmistakable. To the point of this post, until the car reaches S4, it will not do an ICE-off glide unless the glide begins at a speed >34 MPH.)

As another example, on my morning commute I have a stop light, usually red, about 200 yards before I turn left into the office lot. Again, traffic is too heavy for pedal-feathering EV from the light into the lot. But even at the end of this short commute, the car often doesn't make it to S4. So after I give it the gas at the light, the ICE often stays on until I approach my parking space. I watched the ScanGauge one recent morning during this episode. Trip MPG went from 75.4 (at the light) to 74.3 in about 300 yards.

I considered the Coastal switch, as I described here. In the midst of that thread Hobbit made an offer to install a "home-grown" model for me at Hybridfest. Frankly I had been a bit intimidated by others' descriptions of installation; I'm somewhat "mechanically challenged." That's why I first leaned toward what others reported as an easy installation routine offered by the Coastal product. But Hobbit got me thinking: If the home-grown approach is simple enough, and if he has time and the willingness, to do it in the midst of all the activities and hoopla at Hybridfest, just maybe I could tackle it myself. So I began studying the approach with its variations described here and elsewhere.

I primarily used Evan Fusco's instructions, featured (with photos) on CalCars' web site. Thanks to that terrific writeup, installation was a breeze, other than one minor problem of my own creation. More on that in a minute.

I had previously disassembled the dash to install an integrated XM radio unit, so the prospect of removing a couple of vent panels and the lower glove box never bothered me. Harvesting the pin from the steering wheel was a snap. Evan's instructions suggested using a jeweler's screwdriver or paper clip to release the retainer clip on the ECU plug, but I found needle-nose pliers worked better. No problems soldering the wire to the pin. It was a tight fit to get the pin into the plug, but I got it. Needle-nose pliers helped there too. Rather than splicing the ground wire into an existing wire (I didn't feel quite that adventurous), I attached it to a bolt at a metal attachment point of some sort behind and toward the top of where the AC vent dash panel goes. After attaching the ground wire I tested the assembly by turning the car on and touching the wire ends together. I got the expected beep and no ICE activation.

From there, no problem using the coat hanger to snake the wire through the dash innards to other side. My self-imposed problem was with the dash plug to which the switch would be mounted. Per Evan's instructions, I had snipped and cut away most of the fins in the middle of plug's backside. My mistake was not making sure enough had been removed to make room for the plastic nut on the back of the switch. I could have easily -- and should have -- tried the nut before soldering the wires to the switch. But now with the soldering complete and the wires smack in the middle of my work area, I had to delicately cut away little bits of plastic until I could get the nut threaded onto the back of the switch. That probably added about 15 minutes to the job.

But I got it done. The whole job, moving deliberately and carefully along the way and counting the extra time needed to correct my flub, took about two hours, maybe a little less.

And it works like a charm. It performs exactly as expected in that 4-stoplight stretch described above: I hit the switch as I pull away from the first light, with enough electric-only acceleration to get me from one to the next without provoking road rage behind me. I turn it off after I pass through the last one and move on to normal acceleration. At other points in my travels yesterday it was cool to be able to shut off the ICE at will when it wasn't needed and wouldn't shut off on its own.

Those who consider the switch should consider the potential for misuse. The clear consensus among current users is that it could cost fuel efficiency if overused, drawing the battery down so much the ICE runs when it otherwise wouldn't. Over the last couple of weeks I've been preplanning when to use it -- and when not to use it -- during my normal travels. That should reduce any tendency for a knee-jerk push of the button just because it seems at the moment like the right thing.

Who knows how much fuel it saves in the long run. I don't plan any controlled studies. But it's cheap and, it turns out, relatively easy to install. And I'm convinced it will save frustration from seeing the ICE running when I know it doesn't have to. That alone makes it worth it.

[efusco]

Jim's finally coming to "see the light"...Can-View ordered and EV mod #1 done (you'll be dreaming about the nice illuminated OEM button soon enough).

Glad the instructions help.

Although my comments when people ask about FE are "no, don't expect it to help", I am certain that I use it in such a way that it helps my FE...in the conditions you describe and a few others... But that's definately more of a nuance of hypermiling, not a solution for those getting 40mpg and wanting a magical fix and thinking extending battery use will do it.

[philmcneal]

<div class='quotetop'>QUOTE(efusco @ May 26 2007, 07:46 AM) [snapback]450384[/snapback]</div>

Jim's finally coming to "see the light"...Can-View ordered and EV mod #1 done (you'll be dreaming about the nice illuminated OEM button soon enough).

Glad the instructions help.

Although my comments when people ask about FE are "no, don't expect it to help", I am certain that I use it in such a way that it helps my FE...in the conditions you describe and a few others... But that's definately more of a nuance of hypermiling, not a solution for those getting 40mpg and wanting a magical fix and thinking extending battery use will do it.
[/b]

yeah the only reason i'd install ev mode is to truly pulse engine ev glide when in stage 3 or higher,

when having a block heater, your immediately in stage 3 (after idling and letting the engine run in its enrich fuel mode), so in theroy the ev button can help your mileage if you pulse with the engine, then coast and kill the engine immediatly , reaping the benifits, even if your trip is only 1 mile, you can pulse for .2 of that mile and coast the rest, still giving you a good mpg score despite the enrich mode the prius runs in when the ICE first comes on... even when the engine is hot!

why it goes into that mode i have no idea, its truly a waste of fuel. I have can view but no EV MODE, so in theory if i just tap into switch 27 in the ECU, then can i just use CAN VIEW EV button and skip making a button for myself??

[jstack]

I also bought the EV mode option for about $39 from coastal technologies. Just 3 wires connected and I can now force EV mode anytime below 35 mph. It really makes me want the PHEV plug-in hybrid option. They will be available with in a year and I'm ready to get it. 100+ mpg will be sweet.

[Rangerdavid]

thanks for the review Jim, your efforts may give some of the rest of us courage enough to try this ourselves. Meanwhile, enjoy!! (and if you ever come to the mountains down my way, let me know!!)

[JimboK]

<div class='quotetop'>QUOTE(philmcneal @ May 29 2007, 09:50 PM) [snapback]451797[/snapback]</div>

I have can view but no EV MODE, so in theory if i just tap into switch 27 in the ECU, then can i just use CAN VIEW EV button and skip making a button for myself?? [/b]

Hmm, you got me there. I just got word from Norm yesterday that my Can-View was shipping, so it will be a few more days before I get it.

Rangerdavid, my sister lives in Boone, so if I get down there to visit her I'll give you a shout.

[efusco]

I'd forgotten about CAN-View's ability to enable EV mode....that may be your best option while you're into everything Jim.

[JimboK]

<div class='quotetop'>QUOTE(efusco @ May 30 2007, 08:58 AM) [snapback]452013[/snapback]</div>

I'd forgotten about CAN-View's ability to enable EV mode....that may be your best option while you're into everything Jim. [/b]

I just reviewed Norm's site, and from what I can make of it, this is an option only with the optional relay board for PHEV conversions. Am I missing something?

Regardless, I think I'll leave the EV button as is. I'm sure I'll be fiddling with Can-view enough as it is.

[efusco]

<div class='quotetop'>QUOTE(JimboK @ May 30 2007, 08:22 AM) [snapback]452018[/snapback]</div>

I just reviewed Norm's site, and from what I can make of it, this is an option only with the optional relay board for PHEV conversions. Am I missing something?

Regardless, I think I'll leave the EV button as is. I'm sure I'll be fiddling with Can-view enough as it is.
[/b]

Hmmm, I don't know... I've gotten lost in all the various iterations of CV. All I know is that I have a button on the CAN-View screen that shows what EV mode/stealth, ICE spin, whatever and that supposedly there's a place to connect a wire to the CAN-View that makes that button functional for enabling EV mode. I may need an extra circuit or something though...I don't know.

Frankly, I like the dedicated EV button on the dash...it doesn't move and I don't have to change screens to tap it or anything.

[markderail]

My 2006 Prius is rented 4 years. The service manager said not to install the EV, it would void my warranty, and he would refuse to service the car for warranty paid-for repairs if installed.

Not a happy camper.

I am glad that "kits" have been coming out specifically for the Prius (EV-15, EV-30), so when I buy outright the car in 3.5 years I'll simply continue the same monthly payment to pay for the batteries.

From my house to my office is about 4 miles one way, with stops & lights. The EV mode would save me lots of gas...if I could install it.