Help!! Truck locking down in curves!

I have a 2015 Trd Sport and am having a weird issue with what I think to be the abs system. When I take sharp turns, I can hear the system activate. Like a “whining” as if the abs system has kicked in. I could deal with that I think, but the biggest concern is if I’m going down hill into a right hand curve, braking and catching the rumble strips on the side of the road, the brakes seem to lock down. It kinda feels like I ran the passenger side wheels through a mud hole and only half the truck hydroplanes. Has anybody ran into the same issue? Keep in mind that I’ve recently leveled and added bigger tires with a negative offset. Below are the things that I have tried to resolve the issue:

I have had the ABS system checked and reconfigured.

I’ve moved the back ABS sensors to the front and Vice versa.

I have replaced the calipers, and brakepads (didn’t think this would fix it, but it needed to done anyway)

Recently had it aligned.

The only other thing that I think would resolve this would be to put an actual suspension lift on, which I plan to do later anyway.

Any suggestions would be appreciated!

 

Have you done a VSC zero point calibration since the alignment?
If not try that first.
https://www.tacomaworld.com/threads...ibrate-your-vsc-computer-the-easy-way.467485/

Keep in mind that the VSC system on 2nd gens doesn't play well with certain wheel/tire/lift combinations.

 

That seems to have helped. I followed the steps, everything flashed like it was supposed to so Im certain I did it correctly.
I didn’t hear the whine in the regular curves, but it did lock down on me one time on a sharp right hand curve going down hill. Since this is a recalibration of a computer, would it take a few hundred miles to completely calibrate? Or am I wrong in assuming that?

 

This is a very common problem on Land Cruisers (mine does it), 4runners and Sequoia.

After lift and bigger tires, the vsc/abs/trac system has a hard time. My truck will fully lock up one side as you describe in a long sweeping turn. It's downright dangerous and scary.

For 100 series Land Cruisers the fix is to ground a certain wire off the abs module. It disables the vsc or trac and stops the system from trying to compensate. The downside is the system works well to save you in a panic situation (with stock equipment).

 

My truck does not have VSC. But ever the curious I am.
Does this happen when you turn VSC off?
When VSC is Off, doe's the ABS still work? @Dm93 ?

I know on my truck, the ABS is "touchy" in mud and slick conditions.
Early 2nd Gens seem to be worse, the "fix" for us is to pull the 30A ABS fuse.
But that's only for "temporary" occasions. Offroad, snow, mud.....

Obviously, deleting a safety feature is NEVER a good idea.
But getting yanking into oncoming traffic isn't too good either......

Things to consider would be.

Does turning off VSC also disable ABS?
Does discounting the Yaw Sensor kill ABS?

Again, this is just a question of curiosity. Not a suggestion.

 

I'm assuming you mean by holding the Track Off button to disable it?

No that does not disable ABS
Also the VSC system will re-enable itself above 30mph even when turned off by the button, Traction Control will remain disabled however until the switch is pressed again or the ignition is cycled. The only normal way VSC is disabled is in 4L

The only thing that disables ABS by design is if the rear locker is engaged, now weather or not you could provide a switched ground the Diff Lock Sense wire at the ABS module to make it think the diff is locked or L4 Sense wire to make it think it's in 4L without setting a code or causing any other undesirable effects I do not know.

 

That's exactly how the 100 series LC guys disable this unwanted braking in turns. The signal wire when put into 4L or center diff lock tells the truck to disable VSC.

They ground that signal wire and the vsc is disabled with no issue. But things might not be that simple on a Taco.

 

Theoretically that would work on a taco as well as they are switched ground inputs but I don't know for sure.
It's interesting that on a truck without a diff lock the sense wire is fed power from the IG1 No 2 fuse instead of just leaving it ungrounded

 

I had this happen twice in one day during some very spirited driving on very twisty roads at 30-45 mph.

I almost thought a tie rod had snapped or something but it was extremely brief, maybe a quarter of a second. Way to undermine my confidence in how the vehicle handles. The second time I pulled over immediately to check the right front wheel / tire for damage. Nada.

If if eventually gets figured out that it's doable (without excessive other collateral effects) to "hack" the VSC to be disabled I'll probably rig up a toggle switch for it.

For the record, my truck is not stock -- it's about 2.25" lifted front & back on a very solid FOX 2.5 DSC setup + Deavers in back. Tires stock-size P265/70/R16, very tame Yokohama Geolandar G015s run at about 35-40 PSI, depending how hot it is.

 

Is your truck stock?

I've never had an issue with mine, I've even purposely made it activate on slick dirt roads and it does exactly what it's supposed to in keeping the truck straight.


The problem with stability systems is the parameters and calculations are based on a stock vehicle configuration, when you modify that by lifting the truck, adding larger tires, etc you you change the way the vehicle responds to various maneuvers such as increasing body roll for example and the system gets confused and tries to intervene when it shouldn't or may not intervene when it should.

It's even worse on newer vehicles that have ADAS that uses radar, cameras, ultrasonic sensors, and/or LiDAR in addition to accelerometers to help keep the vehicle in control as well as avoid collisions and allow driver assistance such as lane keep assist and distance sensing cruise control. Modifying those (or even doing some repairs) without doing proper re-calibrations or disabling systems that can't be properly calibrated for such modifications can have even worse consequences.

 

I had edited my post above, possibly while you were composing yours -- I added to it:

"For the record, my truck is not stock -- it's about 2.25" lifted front & back on a very solid FOX 2.5 DSC setup + Deavers in back. Tires stock-size P265/70/R16, very tame Yokohama Geolandar G015s run at about 35-40 PSI, depending how hot it is."

It's also a bit top-heavy with an ARE contractor cap + full size lumber rack. If body roll is part of the calculations that go into VSC then the combo of lift + added weight might mean the VSC computer/algorithm thinks the truck is in danger of rolling over when it isn't.

 

It doesn't mention body roll as a factor on 2nd gens but I was talking in general with VSC systems, I know Ford for example has roll stability control in addition to other VSC functions on their trucks, SUVs, and vans.

Some light reading below if you wana take a deep dive into how the systems work