Very cool. Looks like the ZPC isn't too difficult to do should that be necessary, so either way you'll be covered. Looking forward to reading the results of your longer-term test; thanks for contributing!

I believe it is CAN. If memory serves me correct, two of the wires to the yaw sensor are CAN sub bus lines off of CAN-L and CAN-H at the CAN junction. The main bus lines of the CAN junction are fed from the ECM and the Skid Control ECU receives communication identically to the yaw sensor and virtually every other CAN node; CAN bus sub lines from the CAN junction.

If you want to know for sure, probe the yaw sensor connector with a DMM and see if any combo of two wires yields roughly 120 ohms; the impedance between the CAN high and low lines.

This would also mean that either the ECM or Skid Control ECU could store ZPC data, but I can almost guarantee its stored in the Skid Control ECU. It makes absolutely no sense to store safety critical logical parameters in a different control unit. If somebody wants to confirm this, look up Skid Control ECU replacement, I bet it requires ZPC after replacement.

Just looked at the wiring diagram, that's interesting it is on the CAN Bus; not even the dedicated ABS multiplex network.

In any case, like I said if it works it works. But as I said before, if the yaw rate data became modified you wouldn't be able to tell as it's a relative measurement; the only real way you'd know is to do a ZPC everytime. While the chance is probably very small (particularly on '05+ models) that's a margin that can be avoided by disabling another component.

It wasn't condemnation but rather just pointing that out for anyone who would like to disable their VSC this way is all.

Thanks for all the additional background, folks.

I did not get to test it at-length as I had hoped today as I didnt need to drive it far. Next time I take a long drive, I will test it out and report back if there are any ZPC issues or other issues.

My factory "Disable Traction" switch came today, referenced with part # elsewhere in this thread. I was testing it with the ohmmeter and disappointed to find out there is no simple "closed at rest" circuit combined with a "open when pressed" circuit on the switch. The switch as 4 prongs and 2 smaller contacts but no combination of the 6 yeilded the behavior I was hoping (where pressing the switch would momentarily break the circuit.

Instead, I think I will order some generic horn buttons or other momentary switches and try to adapt them to the factory switch so it LOOKS factory from the passenger cabin but inside/underneath the center console, it behaves the way I want with the generic switch. Ill keep y'all posted but any ideas on using the factory switch as a momentary circuit-breaker (switch, not like a fuse of course) would be appreciated.

"GENUINE TOYOTA TRACTION CONTROL SWITCH OEM 84988-35070"
https://www.ebay.com/itm/322141215677

Update:

I turned the switch off to disable VSC/TC for a 1.5 hour drive on Sunday. AS expected, they remained disabled.

Upon restart, the VSC and TC worked normally and they have continued to do so. Conclusion: no Zero Point Calibration needed, at least not on my particular year/model/options/computer setup.

Since the Toyota switch I ordered does not have any "normally closed, open when pushed" setup, I ordered a different switch from Amazon and CruiserHeads 4x4:

CH4X4 Toyota Push Switch VSC Symbol - Amber Led

https://www.amazon.com/CH4X4-Toyota-...pSrc=srch&th=1

I will just toggle the switch on and then off in this circuit i rigged up to disable VSC going forward (just like I do now but right now I have an ugly, generic steel toggle switch in place).

Thanks for getting back!

No Problem

OK, last post for now at least. I wired in the CruiserHEads VSC button I bought on Amazon to replace my ugly Ace toggle switch. Much better now. Check this out. Project "Done"

https://www.youtube.com/watch?v=pRrvR0_COlQ

Hi,
I would like to follow and proceed with this mod.
Please advise if you have had any issues with your T4R since that time?
If all systems are still functioning correctly and in proper way (VSC, TR, ABS etc.)?

I really like this mod versus others and your experience is very important to me.


Thanks in advance.

Any updates on this mod? Theres so much to like about it. Its inside the truck which is great, short run of wires, no park brake lighting up.

Have you seen any down side to your mod. Please check back.

Thanks

Great write up. I found a good switch for the task. It is a “momentary” switch that stays normally closed until I need to disable TRAC. Then press and hold the button until the dash lights up. It has an LED halo ring which will be lit continuously with accessory power, tapped from the wires supplying the USB charger. The button is flat so it doesnt get activated by accident and it’s black stainless so it is durable and blends with the console nicely. The hole size is 16mm or 5/8”.

2 Sets Mini 16mm Waterproof Momentary 1NO 1NC Push Button Round Switch | eBay

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This is one of the best mods so far. Had to use it last weekend after the snow storm. Its great to go old school and have complete control of the truck without the nanny state over riding my inputs.