Disable KDSS with toggle switch?

[LT Ambrose 26]

I have a friend with a trail edition 4runner and he spliced a toggle switch to his stabilizer control ECU.

I'm thinking about doing the same, but he recommended trying to do it as a plug and play solution instead of a slice by getting the matching plug for the control unit and making a harness.

He sent me this diagram (attached) of the plug and I have spent hours trying to Google and find it, but no luck.

The only relevant items I have found are the SCU part number...

2018 Toyota 4Runner REAR SUSPENSION Ride Control CONTROL MODULE - OEM Toyota Parts

... And some kind of diagnostic page.

Toyota 4Runner: Suspension Control ECU Communication Stop Mode - Can Communication System - Service Manual

Can anyone identify the plug itself or know where I can get one to make my own wire harness?

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[Mutant138]

Add quick disconnects to that mod FTW.

I think quick disconnects would be a better use of time*

 

[LT Ambrose 26]

Add quick disconnects to that mod FTW.

I think quick disconnects would be a better use of time*

But adding quick disconnects, you're saying instead of a "hard" splice I could make it so the wires I splice to can reconnect back to themselves if I want to remove the switch?

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[euser]

Why? I never understood why people spend thousands extra for something they’re just going to remove or disable.

 

[mitchell.marsh]

I don't understand the use of the ect power button. cay anyone please clarify me?

 

[jrandom]

Why? I never understood why people spend thousands extra for something they’re just going to remove or disable.

Why? Why disable ATC or any other toggle-able feature. Why roll down your windows when you have climate control. Why use 85 octane when you can use the recommended 87?

I know what you are saying, this is completely different. You can enable OR disable when you want too. This isn't simply removing of permanently disabling something.

More akin to deactivating traction control so you can do donuts or simply practice driving in slick conditions. You have to lose control in order to predictably regain it.

IIRC KDSS only goes "limp" in low range and less that 12mph.

 

[Akkording]

I don't understand the use of the ect power button. cay anyone please clarify me?

ECT PWR button will adjust shift points so you can reach higher RPM levels before shifting into the next gear.

On the Tacoma it helps will pulling a load, it holds a higher rpm on the torque converter before shifting. It's like the Turbo button on 286/386 PC's, no it isn't.

 

[LT Ambrose 26]

Why? I never understood why people spend thousands extra for something they’re just going to remove or disable.

Well the idea is that splicing a toggle switch allows me to select when to have it enabled or not.

My understanding of the KDSS system is that below a certain speed (something weird like 12mph) it allows the suspension to articulate more, such as when you're going through a technical section off road. And when you go above than speed it's assumed you're on pavement and it stiffens the suspension to give you better handling. The drawback is that if you're going down a relatively easy dirt road then you'll be exceeding the speed threshold and the suspension will behave stiffly. If you use a toggle to disable the KDSS then you can maintain a softer suspension above that threshold so that if you drive over a rut for example the whole vehicle is less likely to shutter as when the KDSS is enabled and the suspension isn't allowed to flex as much. This is more or less the explanation my friend gave me when he was describing why he did it.

So the goal isn't to remove the KDSS or permanantly disable it either. It's to enable the vehicle to have more give in the suspension when you doing something with some speed but with unexpected bumps and such.

 

[HanginInUtah]

I think this would be a great idea.

I haven't done much research yet, tho, and I know there is at least one other thread about this. I think that thread has some testing with removing the fuse, and whether lights come on or not, etc. I'm wondering if it could be that easy? Instead of splicing into anything, connect into the fuse location with an inline fuse and a switch? That way it's a) not permanent, and b) not splicing into existing wiring, running the chance of introducing issues. A thought I just had: I wonder if turning the power back on would require a key cycle for the system to re-initiate...

Just my thought.

I agree with your purpose you have in mind.

 

[Jetboy]

Well the idea is that splicing a toggle switch allows me to select when to have it enabled or not.

My understanding of the KDSS system is that below a certain speed (something weird like 12mph) it allows the suspension to articulate more, such as when you're going through a technical section off road. And when you go above than speed it's assumed you're on pavement and it stiffens the suspension to give you better handling. The drawback is that if you're going down a relatively easy dirt road then you'll be exceeding the speed threshold and the suspension will behave stiffly. If you use a toggle to disable the KDSS then you can maintain a softer suspension above that threshold so that if you drive over a rut for example the whole vehicle is less likely to shutter as when the KDSS is enabled and the suspension isn't allowed to flex as much. This is more or less the explanation my friend gave me when he was describing why he did it.

So the goal isn't to remove the KDSS or permanantly disable it either. It's to enable the vehicle to have more give in the suspension when you doing something with some speed but with unexpected bumps and such.

This is correct. The shutter valves (solenoid valves) close over 12mph and the result is that the accumulators (reservoirs) are disconnected from the system. Opening the valves softens the sway bar effects.

I wish I knew more about the engineering decision to close off the accumulators. It could be that it was simply to firm up the suspension. That seems most likely. But it is also possible that it could be due to some part of the system generating too much heat. That's what concerns me and I wish I knew more.

Good luck. Let us know how you like it.

 

[Mutant138]

But adding quick disconnects, you're saying instead of a "hard" splice I could make it so the wires I splice to can reconnect back to themselves if I want to remove the switch?

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Negative ghostrider. Talking about where the sway bar is attached to the truck. Disconnects would allow you to get full articulation without being limited by the kdss system. Then when you want it back just hook em back up. Think certain jeeps come with electronic disconnects so you can just push a button. Old school way is literally something you unbolt or un pin.

Essentially you would negate the whole kdss LT issue (someone correct me if i'm wrong here). You would prob need the trac bar from sonoran steel and extended travel shocks to really take full advantage.

Would be something you could easily return to stock. However i don't think anyone has figured it out with kdss as the sway bars don't really have traditional endlinks.

Edit: I re read and realized your mostly talking about the high speed dirt road issue.... I'm game for an off button for that purpose. Disconnects like I'm talking about would be dope combo with the off button for whatever the road brings.

 

[Bumbo]

This is correct. The shutter valves (solenoid valves) close over 12mph and the result is that the accumulators (reservoirs) are disconnected from the system. Opening the valves softens the sway bar effects.

I wish I knew more about the engineering decision to close off the accumulators. It could be that it was simply to firm up the suspension. That seems most likely. But it is also possible that it could be due to some part of the system generating too much heat. That's what concerns me and I wish I knew more.

Good luck. Let us know how you like it.

Now that you mention it… I am curious about the engineering decision behind it too.

12 mph isn’t very fast… my regular cruising speed on trails is probably anywhere between 15 to 35 mph with my current suspension and I can see why people would want the switch.

Just like a shock absorber, the more you work it, and the faster you work it, the more heat it will generate. Might be wise to monitor thermals.

 

[Jetboy]

Negative ghostrider. Talking about where the sway bar is attached to the truck. Disconnects would allow you to get full articulation without being limited by the kdss system. Then when you want it back just hook em back up. Think certain jeeps come with electronic disconnects so you can just push a button. Old school way is literally something you unbolt or un pin.

Essentially you would negate the whole kdss LT issue (someone correct me if i'm wrong here). You would prob need the trac bar from sonoran steel and extended travel shocks to really take full advantage.

Would be something you could easily return to stock. However i don't think anyone has figured it out with kdss as the sway bars don't really have traditional endlinks.

Edit: I re read and realized your mostly talking about the high speed dirt road issue.... I'm game for an off button for that purpose. Disconnects like I'm talking about would be dope combo with the off button for whatever the road brings.

The KDSS cylinders are the end links along with the two fixed linkages. So the way you could theoretically have full disconnects would be to have the fixed side links modified to have a disconnect. The KDSS cylinders are under pressure to extend - so getting the them back connected would require more than just aligning a push pin.

The main issue in most cases is simply the limited range of travel. I'd love to have a KDSS system like the LC200 that has much more range of travel. I think it could be done on the 4Runner. The rear would need a linkage with a longer travel lever arm. The front would need the brackets on the control arms moved inboard about 2 inches and a narrower sway bar made up to fit (basically just change the leverage on the control arm). But the suspension is limited by a lot of other factors anyway, so there's not a lot of benefit to be had unless you fix the other issues like adding longer links, new brackets, longer control arms up front, etc.

 

[Jetboy]

Now that you mention it… I am curious about the engineering decision behind it too.

12 mph isn’t very fast… my regular cruising speed on trails is probably anywhere between 15 to 35 mph with my current suspension and I can see why people would want the switch.

Just like a shock absorber, the more you work it, and the faster you work it, the more heat it will generate. Might be wise to monitor thermals.

The LC200 KDSS is always "open" and the LX570 uses accumulators for basically the entire suspension system operation as shock remote reservoirs. Assuming they share the same internal designs - I'd guess the real desire is more firm driving rather than heat - but we just don't know. There may be some restrictions in the system that generate a lot of heat. It would probably be worth running it that way for a bit and using a thermometer laser gun to check the temps of the components just to see.

 

[Akkording]

How about disabling KDSS at the fuse box under the dash labeled #26. Is that an option? I have no clue what domino effect this might cause to the 4x4 system or traction controls


I don't know much about 4runners just basic SR5 PoorRunners and 1st gen Tacomas

 

[honda250xtitan]

Add quick disconnects to that mod FTW.

I think quick disconnects would be a better use of time*

hard pass. KDSS isn't that easy, plus quick disconnects make a racket. A switch to leave the system "open" would be fantastic. other guys have simply unplugged the harness from the system on the frame rail below the driver door, this inline switch has also been discussed, but that thread kinda died off.



IIRC the only light that popped up was the KDSS light when disconnecting the plug. OP did you read through that other KDSS disconnect thread?

 

[honda250xtitan]

Here ya go, post 34 it gets juicy... Only KDSS w/lift need apply

"""Did some testing today.......... Pulling the fuse locked my kdss in highway mode, very stiff at 5mph and no change at moderate speed.... But! (With the fuse in) Unplugging the kdss module on the frame rail area locked mine in low speed mode!!!!!! So I could hit that 10-20mph and still have the more plush ride, the kdss dash light is lit up with either method and it turns right back off when plugged back in!, I can feel slightly more body roll on the road but I feel as if even though it stays in low speed mode and I get a softer ride, the valving in the system is only so big so at 25-30 it feels somewhat similar, but I also was testing with street pressure and it was a good test, can't wait to air down and have a day out on it... Driving into parking lots also felt softer on my typical run to the grocery store, so this will even help out the mall crawlers..����

Next is to wire in a switch to maybe the power wire going to the module so I don't need to take off the cover to change it, but it would really only be there if the kdss light gets irritating at night.""""

 

[LT Ambrose 26]

Here ya go, post 34 it gets juicy... Only KDSS w/lift need apply

"""Did some testing today.......... Pulling the fuse locked my kdss in highway mode, very stiff at 5mph and no change at moderate speed.... But! (With the fuse in) Unplugging the kdss module on the frame rail area locked mine in low speed mode!!!!!! So I could hit that 10-20mph and still have the more plush ride, the kdss dash light is lit up with either method and it turns right back off when plugged back in!, I can feel slightly more body roll on the road but I feel as if even though it stays in low speed mode and I get a softer ride, the valving in the system is only so big so at 25-30 it feels somewhat similar, but I also was testing with street pressure and it was a good test, can't wait to air down and have a day out on it... Driving into parking lots also felt softer on my typical run to the grocery store, so this will even help out the mall crawlers..����

Next is to wire in a switch to maybe the power wire going to the module so I don't need to take off the cover to change it, but it would really only be there if the kdss light gets irritating at night.""""

Thanks for the link. I'll give this a read through when I get home and see if there's a solution in there.

A brief scan showed it looks like they were looking at a different harness.

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[Akkording]

[MENTION=83083]rigtec[/MENTION]
Are you aware of any potential switch solution without the manual undo of the harness?

 

[Alexm963]

Where is the module located? I just got my 4Runner this weekend and haven’t looked for it yet. I’ll see what I can track down for the connector. I just spent some tome doing that for another project on it.