This question was posed to me by my good friend with an ISF and i was directed to the this thread in the ISF section. So i wanted to inquire in this section

https://www.clublexus.com/forums/is-...gas-pedal.html

I saw in the ISF section that there is a "throttle kickdown button" behind the gas pedal. Apparently when you floor it, you havent actually floored it until that button behind the pedal is "clicked". After i saw this thread i went out to my 350 and there was the same button behind the pedal, the only thing is, its not as tall as the one pictured in the ISF which lead me to wonder if it is in fact the same feature at all.

Im not sure if anyone in the 250/350 section has noticed this as well, but, I figured i would ask. Since ive had my car over a year and just noticed that black button tonight. Any info on it would be awesome

 

Here is a visual in case anyone was confused as to what I meant

 

The button is hollow on the ISx50...its just plastic with no "button" and no wire sending feedback to the engine/tranny ecm, serves no function here.

I learned this while doing the ISF swap on my IS350. The ISx50 trannies do not utilize the switch while the AA80e 8 speed does.

 

^If anyone would know...it would be you! LOL

 

As was stated, it's just a pedal stopper, nothing more. Lexus added a switch to it for the IS F.

Jeff

 

Yeah its in here somewhere lol

Also, that big blurry white wire plug/sensor atop the brake pedal.....why would lexus give us a different "Stop Lamp" sensor than that of the ISF? The things I'm learning....

 

Damn, Just learned something about the IS-F. That's dope. I knew we had it, but thought of it as a stop pad for both.

 

The stop lamp switch is the same in the ISx50 and IS F.

The 06-07 is different than the 08-13, but the ISx50 and IS F are the same.



Jeff

 

Gotcha, thanks! It's the same 4 pins just different size wire harness/plug.

 

I have this kickdown button switch on my 2012 250 Fsport and it works just like a kickdown switch. It switchs to the lowest gear possible (usually 2nd gear) and accelerate harder when depressed than without.



You can see in the photo that I have pressed the button with my fingers.

 

Lexus added it to a recent year isx50 but not sure which (maybe 2012?). For sure the 2014 with updated tranny

 

There is no mention of the kickdown switch being added to any 2IS other than the IS F in any of the wiring diagrams, repair manuals or parts catalogs, they all list the same thing from 2006-2013.

In other words, that's super weird, and if it IS a switch, what's it connected to?

Madness.

Jeff

 

Jeff, I know its added on the 2014 due to the tranny....
No clue if at some point lexus started adding it to prior year ISx50 aside from the ISF that we know. It is def. a dummy plate on my 06. The actual sensor uses s 2 wire connector common plug (90980-11156) and sends a signal to the tranny ecm and or the engine ecm. Lobuxracer detailed out the functionality in the F forum.

 

I definitely feel the difference when I accelarate in Normal mode by pressing it then without. As I wrote before, it instantly drops a gear lower and accelarate with full power then not have it depressed.

My car is Euro spec. Maybe its difference equiped to your NA cars?

 

Right, I was speaking of the 2IS only.

I was just thinking that on the way to work after I checked at home that maybe it's a different market, and it is. The 2IS used the kickdown switch in many automatic export-spec (namely Europe) cars from the get go in 2006, it was also added to some other markets in 2011.

Japan and North American 2IS ISx50 models never used it.

Jeff