2006 Prius Factory EV Button Installed

After searching high and low, I could not find any documentation on how to install a factory ev switch in an '06. However, I decided to undertake the effort anyway using these instruction as the main document, and this one for the factory button info. I ordered my switch from Sigma Automotive (be sure to specify your year in the comments). It arrived yesterday, and I gave it a whack today. I learned a few things, which I'd like to share, and then end with a question or two.

• Be careful, some of those parts under the dash are sharp! Just ask my pinky...
• The description of the ECU connector where the pin goes is still accurate in an 06. As is the ground wire.
• The EV button will not fit in the left most opening. That one has a slightly different slot configuration.
• The Sigma kit came with some ~ 4 inch lengths of wire with pins already attached for the button and the ECU. The pin for the ECU was a very tight fit. So tight, in fact, that I broke it while trying to get it all the way in. Swearing ensued, but I robbed another pin from a radio shack db9 connector I had lying around. I widened the hole with my jewlers screwdriver and got it this time.
• I don't know about an 04/05, but fishing that coathanger behind the dash was easier said than done in my 06. I had a devil of a time finding an open path. Pulling the wires back through was equally troublesome as they kept getting snagged and coming off the coathanger.
• The factory button doc lists pins 1 & 2 as the illumination wires, and 3 & 4 as the EV wires. It didn't specify which pin was which, but I assumed they were starting from the top to bottom. I tested the 06 switch with my multimeter, as he did and found the pins were different. I observed continuity on the outer two pins with the button pushed, and not with the button open - clearly those are the switch pins. So the inner two must be the illumination pins though I didn't measure any ohms on those two pins like the doc said. There were, however, red and grey wires on the dimmer control as the doc described, so I hooked those up. End result? Starting at the top, pin 1 = EV-, pin 2 = Ill-, pin 3 = Ill+, pin 4 = EV+. **
• Use a full size, regular pair of pliers to snap the radio shack telephone connectors closed. A pair of needle-nose just makes then snap unevenly and likely to pop out in the process.

EV Mode works just great, but I get no illumination. I started to doubt myself, and tried rearranging the pins as described in the original docs. I got illumination then, but it worked backwards from everything else. It was bright when they were dim, and dim when they were bright. So I started experimenting with various configurations of pins, which I think may have been a mistake. No matter what configuration of pins I tried (even the one that was working but backwards) I got no more illumination. And now, when I adjust the illumination brightness, it reaches full bright well before the "click" point and the illumination on the radio and MFD flickers inconsistently.

OK, so now my questions. 1) Why didn't illumination work? Did I get the pins wrong?** Did I tap the wrong wires off the illumination controls? 2) In my experimentation, did I fry the illumination control? Why is the brightness off whack now, and why do the radio and the MFD not illuminate properly?

I hope this helps somebody, and I also hope somebody can help me.

** EDIT: Corrected the pin labels above in case anyone is searching for this, I don't want them to get it wrong. Also, note that there are links in a follow up post to another writeup on the subject.

 

Hmm. It's worse than I thought. The MFD and radio actually flicker in brightness pretty much any time the rheostat is set to anything less than full bright... Can anyone help?

 

<div class='quotetop'>QUOTE(Ari @ Oct 2 2006, 07:16 AM) [snapback]326825[/snapback]</div>

Doh. Why couldn't I find those when I was looking? Sounds like I got them exactly backwards. + on the - for both ev and led. I'll try reversing them.

 

OK, I flipped the pins around as described in the links you gave. Nothing like doing a little Prius modding in the parking lot at work, eh? EV still works, but I can't tell if the illumination works or not 'because it's too bright out there. BUT, the MFD and radio still flash when adjusting the rheostat. Anyone out there know enough to tell me if I've hosed the rheostat or something worse?

Thanks!

 

<div class='quotetop'>QUOTE(Pinto Girl @ Oct 2 2006, 12:02 PM) [snapback]327000[/snapback]</div>

I can't speak for other Prius people, but I was weird even before I got my Prius. :lol:

 

OK, I've got it fixed!!! A friend of mine who is a bit more knowledgeable about automobiles and electronics suggested I check my fuses. Sure enough, the 7.5A "panel" fuse was blown. Pick up a replacement, and between that flipping the wires everything is perfect now. Phew. B)

 

<div class='quotetop'>QUOTE(Ari @ Oct 3 2006, 03:53 PM) [snapback]327569[/snapback]</div>

You bet...

 

<div class='quotetop'>QUOTE(Ari @ Oct 3 2006, 03:53 PM) [snapback]327569[/snapback]</div>

As requested, here's my one week EV mod review... There have been a number of other threads here discussing the EV mod and whether it's worth it, how you should use it, etc., so I don't see the need to delve into that too deeply here. I'll start off by saying that my motivation for doing this was nothing less than "because it was there". I did it because I could, not because I actually thought it would help mileage any. I'm a geek, what can I say?

I haven't really noticed any mileage improvement, but the car is so new I haven't really established what's normal yet anyway. I do find that I like to use the EV mode for scooting around parking lots and when pulling out of my driveway/neighborhood. The EV range isn't real great, but works just fine for the way I've been using it. It has certainly whetted my appetite for a PHEV mod or a battery capacity mod, though those are quite expensive - I probably won't do it.

From a functional standpoint, I find that maybe 1/4 of the time (or less) the car won't let me enter EV mode because one of the restrictions such as low battery is in effect. When this happens, the MFD will display "Can Not Enter EV Mode Now" so there's no question what happened. Though it's not always as easy to know when it has entered EV mode. Sure, the MFD will switch to energy mode, but it stays there when EV mode kicks out. So unless you switch it to something else because entering EV mode again, it'll already be on that screen and so there's no change to observe. I wish that when it kicks out of EV mode it would return to whatever screen it was originally on before entering EV mode. It also seems that there's no explicit way to cancel EV mode (other than maybe stomping on the accelerator). Ever so often I want to cancel EV mode, and pushing the button a second time doesn't do anything... Oh well.

So, in summary, unless you're a geek who wants to do it just because you can it's probably not worth the effort. It's almost certainly not worth the cost of ordering a JDM switch, unless you're really set on getting that stock look. Would I do it again? You bet.

 

<div class='quotetop'>QUOTE(Allannde @ Oct 8 2006, 08:18 PM) [snapback]329913[/snapback]</div>

I was just about to correct myself. You're right, it does, but it isn't always easy to tell because the engine may well decide to stay in electric on it's own.