wiring EV switch to steering wheel control

I got curious too as I have a 2006 #6 and researched it some. It doesn't look like we can use the map button for anything . It is essentially multiplexed with the auto, temp +, and temp - buttons on the left hand side of the steering pad. I susepect the button even puts out a signal (via the A/C ECU) on the BEAN and AVC-LAN, but the nav system is the only thing looking for it.

If you want to dig through the electrical diagrams, see the attached .pdf files ( I hope this works) and then the links in the thread at www.tundrasolutions.com/forums/prius/59638-2006-pius-steering-pad-map-spare/

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You could still use the button but you would essentially have to design a duplicate amplifier/circuitry that senses the different voltage present on the bus when the MAP button is pressed. This would require analog comparators or a microcontroller with analog input. Not terribly difficult but it's no longer just a switch closure like the headlamp flasher or cruise control disable options.

 

You'd have to build a fairly sensitive window comparator, and know
what voltage is produced when that button is pressed [easy enough
to test]. My guess is that the unseen resistor in the chain [inside
the ECU, probably] is 1K, yielding button-press readings of .25,
.5, and .75 times the supply voltage. Just like old wired remotes
used to work, heh...
.
How much of the '06 manual is up at tundrasolutions? It won't let
me grab things without "registering" [grrr] but that might be a
handy resource for those who are tired of TIS.
.
_H*

 

Only some of the 06 electrical is in the Tundra
Solutions knowledgebase. I can download stuff with the normal (free) registration. A lot of the info available is TSB's.

 

What they are saying is that all the switches on that steering wheel "pod" have a common output wire. The computer knows what button you have pressed because each button provides a different voltage on that wire. That means you can't easily use any of the buttons for another use.

 

sure, if you don't mind letting everybody ahead of you know when
you're switching modes, and potentially confusing them as to
what you're trying to communicate.
.
I'm still surprised that the headlight-flasher method has gotten
so popular. It has some *really* unwanted side effects.
.
_H*

 

neither did my generic pushbutton...
.
_H*

 

Say what? :blink: The headlight-flasher method only has 2 side effects that I'm aware of:
1) You can no longer blink your lights during the daytime by simply pulling on the stalk. No biggie, I never do that anyway. You can still blink them by rotating the headlight switch, if you wanted to.
2) If you happen to want to engage EV AT NIGHT, when your lights are ON, it will blink your high beams at the same time. OK, how often does that happen? How often are you on a road, with uncoming traffic, at night, and you decide to engage EV? VERY rarely, in my experience so far. A minor inconvenience, IMHO.

 

That's true. I have the Coastal mod mainly because I know my skills at installation. I don't use the "flash to pass" part either so that side effect wouldn't affect me. One big advantage the EV/flasher mod has over the EV/Coastal mod (aside from price) is the fact that the headlight stalk is always on the left side of the steering wheel, whereas the CC stalk turns with the wheel so you have to figure out where it is at times.

 

I would like to engage EV at night more often, but in trying not to avoid irritating or confusing the drivers in front of me, I avoid using it.

The advantages of the head light flasher mod over the Coastal mod or a separate switch is the instantaneous switch into the mode (no delay like Coastal) and handy access (separate switch). I'm wondering if I can wear out the headlight stalk switch, as much as I would like to use EV though.

Also, installing the HL flasher mod removes the connection for the daylight headlight flash. I wonder if you can remove the night time flasher as well by removing an additional wire. I'll have to look at the schematics.

 

Having used the headlight flasher mod for two months, I'll throw in the following observations.

You can still 'daytime flash' folks by pulling the stalk, but as noted, only if you leave your low beams on during the day. (Which many folks do, as Daytime Running Lights, or because they let the car turn them off at night on it's own).

You can also 'daytime flash' folks by twisting the knob.

It should be possible to wire up the mod so that you don't loose 'daytime flash', but I'd want to look over the electrical schematics first just to be 100% sure.

As to nighttime flashing, it's really a non issue. At least in my case, I really only flip into EV mode when stopped (be it parked, or at a red light, etc..). The car so rarely lets me slip into EV mode at speed (unless I'm really crawling slowly), that I rarely bother.

And even so, all it takes is a split second of contact to activate EV mode. The high beam blink is so short, most drivers would probably think you just hit a small bump and it bounced your beams higher for a second. When someone wants to flash you with their high beams - they're usually quite noticeably obnoxious about it, which the side effect of the EV mod isn't.

Just my 2c

-Ken

 

Hey... who you calling pissed? :angry:

 

I do a lot of my driving at night, many times when I want EV I don't feel like I should have to flash my highbeams at anyone. Thats why I went with the factory EV switch.