Traction control

Assumptions really aren't getting you very far.

Thinking diff or tcase fluid in any way has an effect is so far out in left field I don't know what to say. I've tried to lay out the items at play here and those are the items I'd be systematically testing and eliminating.

 

Ok thank you. You have been the most helpful person in this. As I'm not really that mechanical savy when it comes to this i was just throwing out ideas as far fetched as they be. I tend to overthink. But when i get a chance i will try and check the connections to the steering like mentioned.

 

A triggered intervention is caused from some system the VSC/TRAC uses. Steering, wheel speeds, and inertial parameters. That's it.

Sensors so far have checked out fine: steering angle, wheel speeds, yaw rate, lateral/longitudinal accelerations. We at least know they're working and zero point calibrated, but we're not 100% sure they're accurate. However the odds of them working, not throwing a code, AND being inaccurate is very low.

Therefore, it's time to investigate the physical properties of the systems that are being measured. Steering is the low hanging fruit.

 

Quick update. So I did climb under my truck myself and move the steering around. I did notice that I guess the steering rack is on isolation mounts. I wasn’t able to determine anything loose myself but I did drop it off at Toyota. They have been doing an in depth inspection. Oddly during there drive they had a code pop up which has never showed that they pointed to the abs actuator. Turned out to be an expensive repair and what they thought was the problem. They ran through a series of tests and checking stuff. Did rotate tires and find that one wheel speed sensor was loose. But now after 2 weeks they still can’t seem to find out what’s wrong and are trying to pull the blaming it on the lift and want me to remove the lift. I’ve been in a loaner car from them. Plan on letting them continue to check because we know that’s not the problem. They said there’s a clunk
Noise when that light clicks on and they say it’s in the axles. Ive only heard a clunk from the front when I come to a stop and the nose dives and rebounds after braking. I know 4 wheel parts ran tests with it and said the yaw was going haywire and suggested stiffer springs. But first to go to Toyota. I’m looking into the law that states they have to prove the lift is what’s the cause of the issue.

 

Use techstream, plot yaw rate, go for a cruise, and see if it does anything weird. Check wheel speeds and accelerations while you're at it. That's all very easy to eliminate. One more time, get a helper to rock and turn the steering wheel while you inspect from underneath. Still yet nobody else's random guess fits the problem as well.

There's a reason my vehicles never go to a shop or the dealer and you're experiencing it. Inability to actually problem solve. Nobody cares as much about your truck as you do.

 

Well final update. After the truck sitting at toyota for a month searching the ecu and all the rates trying to tweak stuff. They found the front wheels binding while on the lift. When it would bind you could see the upper and lower control arm move up and down. They kept wanting to either add a crazy expensive diff drop or just remove my lift all together. I showed up and took a look. Moved the steering while on the lift. Spun the wheels all while recording then took my truck back. Toyota clearly didn't know how to deal with small lifts and didn't get what i was saying.

I did run a test again on techstream and still looked normal but now with the binding issue known I knew the main cause of the problem. Hazzard fab chose to use bilstein 5100 shocks which is fine but they set the struts at the bottom notch with the stock springs and instead chose to lift with a top strut spacer. Well the strut still has all the downtravel if you did a spring lift. So it was allowing for more downtravel and body roll inducing the front cv bind. So I talked to hazzard fab and showed them all the issues and troubleshooting i've had done. They tested this by first removing the top strut spacer. The wheels spun freely while on the lift after removing the spacer. They then swapped to the proper spring OME888 for the lift i wanted and it still spun freely. I've been driving around for 2 weeks and 99% of the issues are gone. I believe now its only going off in situations where it should or would be normal for a lifted tacoma based on my readings. And thats pushing it. I can now drive around normal circumstances without the light flashing on me.

Thanks for all the help especially Shimstack. Oh and hazzard fab didn't charge me for this fix. They wanted to make it right which i'm thankful for.

 

Sad to say it only took a couple weeks for the problem to come back. After finding out i had a rubbing rear brake pad it helped a little. But kinda just dealing with it right now.

 

Im having the same exact problem on my 2018 toyota tacoma sr5 4x4
The traction light would flash on any turns and then the abs would kick in after if flashing to long
Ive done
-all zero point calibrations
-Changed both wheel bearings
-Changed speed sensors on all wheels
-Put back my sway bar (Drove a year without no problem)
-Tried running oem wheels (Still flashed)
It all started after changing my steering rack (which was a problem bushings were out) and we changed my steering angle sensor / clock spring.
I believe changing the steering angle sensor could fix this with a alignment and zero point calibration. Im no mechanic but after trying months on end anything to find the source of this problem the only thing I can think of would be the steering angle sensor. Instead of using the oem part I bought one on ebay the chinese version and the light started flashing on turns. I wasnt getting any codes to pop up but according to toyota dealership they found c1445. So I think even though my steering angle sensor is brand new I need to have it professionally done and the oem part

 

I am having the exact same issue originally my steering angle sensor failed due to a failed battery which is ridiculous but I ended up buying the cheap eBay steering angle sensor now I have intermittent slip indicator light flashing what was the end result for you did you end up putting a oem SAS in did that solve your issue?