Originally Posted by LoSt180

It's doing what it's named for: kicks down the transmission to a lower gear. In my test, at 60mph it's the difference between dropping to 4th or 3rd gear.

It's actually an old tech feature. End result is that the car goes really fast, or it believes you really meant it and engages ludicrous speed.

Originally Posted by lobuxracer

The switch impacts WOT. If it is not mashed solidly to the floor (which takes more effort than I deem reasonable in an '08), the car does not accelerate as quickly.

Originally Posted by JT2MA71

I took care of that stiff switch on my RCF. Here are some pictures I took when I did it.







Taken apart.


Showing 3 springs after cutting.

Originally Posted by lobuxracer

So back on topic - I've always hated the force I needed to apply to get the kick down switch to work, so I decided (inspired by this thread) to solve the problem tonight.

Removing the switch is a bit of a pain, but not too bad. Unfortunately, if you want to remove the switch, you either need to break a small piece of polystyrene foam or remove the entire carpet. I opted for breaking the foam piece.

Once you have the switch out, the observant student will see where the two releases are on either side of the switch. Push them in with a small screwdriver and the switch assembly can be carefully pulled out of the metal bracket which holds it securely in the car.

Next, take the same small screwdriver and release the three catches at the bottom of the switch. This will expose the main spring and the center rod in the switch. Remove the circlip from the center rod and carefully pull out the top of the switch.

Now the (sort of) tricky part. Push the center of the switch assembly slowly towards the end where you removed the cap. There is a LOT of very sticky grease in this thing, so it will take a bit of pushing. If you push too fast, four ball bearings will fly out of the assembly and do their best to disappear (as all ball bearings do when released from captivity). If you are careful, you'll get all four of them because the grease is very sticky (did I mention the grease is VERY sticky?). Inside the center body are two springs which look like ball point pen springs. They are responsible for the initial stickiness you feel when you press the gas to the floor because they're the detent *****. I cut about 1/8" off both of these springs then put the ***** back in place to reduce the amount of effort I need to use to get the switch working. Put the circlip back on the center post after installing the top of the switch.

Before installing the main spring, cut one full revolution off of it. This does make the spring stiffer, but since we're not extending the free length of the spring, we're reducing preload AND stiffening the spring a little. Both actually work in our favor here. Now install the bottom cap, and put the assembly back in the metal bracket and install in the car.

I can just barely feel the switch engage now. It's EXACTLY how I think it should have been from Lexus. Just enough feedback to know you're on it, but not requiring an extra push just to get the gas to the floor.

It feels better to me, AND it only cost me about a half an hour.

NO, I didn't take pictures. This isn't a mod for someone who barely knows the difference between a common and a phillips. Anyone who's been working on stuff like this will be able to easily see what I did once they have the switch out, and they'll be able to make the changes I described without permanently ruining an expensive part.

FWIW, if the switch goes permanently closed, the ECM will ignore the switch, so shorting it out is a bad thing.

Originally Posted by TinCan

Cutting of the springs, the bigger spring is much harder to cut. Also, if you take your time on the re-install the foam doesn't break.

Originally Posted by nan88

Kickdown switch modification from the RC-F / IS-F sub-forums, applies to a vast majority of Lexus & Toyota vehicles.
Quick 30min DIY. The modification makes the switch much easier to depress and linear.

TL;DR (Switch function) -



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

Originally Posted by nan88

Yes, same exact instructions.
Very easy, fast, and free mod.
Mine was super stiff, now it rolls into the kickdown switch naturally and I can hold down the pedal with less effort.