Trailer Sway Control

I'm considering trading in my '06 for a new Tacoma with towing package. The package comes with "trailer sway control", which, according to Toyota's brochures, is an electronic system that actuates trailer brakes for sway control (footnote 25 in disclosure section of brochure). Anybody know how such a system works? How does a sensor on the truck know how to apply trailer brakes to reduce sway? Does it apply both brakes or just one side? Seems like the mechanical systems that use friction would work easier. Or, I could just use the lever on my brake controller that applies trailer brakes without using the truck brake pedal, right?

 

That's a good question, my answer is I don't know. Just a guess, maybe the truck senses the rear end of the truck swaying and sends some signals through the 7-pin to the trailer brakes? I've been in some stiff crosswinds and I have no idea if or what the truck does to compensate. I figure the trailer sway control would only engage if you engage the brakes?

All I know is the trailer I have, with a straight hitch does well in crosswinds. I HAD the Equalizer WDH with 4-way sway control, and tore it up going mildly offroad. That hitch was bent, the hookup on the trailer side was sliding no matter how much I tried to torque it down. Even the giant bolts on the truck side came loose, had to get them impact-wrenched again at Camping World.

I finally said enough of this, I'm not gonna pull that hitch every time I go off a paved road. Went to the straight hitch for $36, put some Timbren bumpstops on the rear, and so far so good. There's better options for the rear end for towing, more expensive and fool around with the stock geometry, but all in all the truck does well with just the straight hitch.

 

I do believe it only works the truck brakes .

 

As I understand it:

It applies the trailer brakes by themselves. Most (if not all) trailer brakes cannot be applied one side at a time and an 7 pin connector does not provide that option. Once it detects sway caused by the trailer, it will apply the trailer brakes. By applying the trailer brakes, it creates a huge load on the truck causing the entire train to straighten out. (think of pushing a wet string into a straw versus pulling a wet string through a straw.) How it detects sway of the trailer, I don't know. Again, I could be wrong, but that is how I understand it.

 

I think I have the answer and Lucky Charm, is, I believe, correct. Somehow (don't know how) the system senses when a trailer is attached and, under bad sway, it applies both trailer brakes. At least that's what the dealership said when I asked the question.

 

Made me curious, I still have not even had time to go through the manual, not mess with VSC. Anyway, this is what it says:

■ Trailer Sway Control (vehicles with towing hitch and 7 pin connector)
Helps the driver to control trailer sway by selectively applying brake pressure for individual wheels and reducing engine torque when trailer sway is detected.
Trailer Sway Control is part of the VSC system and will not operate if VSC is turned off or experiences a malfunction.

Interdasting. Still, how it detects sway is unclear. If it operates in unision with VSC, it must rely on those sensors, but how the hell would it pick up lateral wiggle?

And yeah, If I have a trailer big/heavy engouth to sway, I'd want to just use traditional trailer brakes to straighten it out.

 

Okay. I know that this is an old thread but I experienced either the sway control or the VSC system activation today while I was towing a trailer loaded with about 3,000 lbs. of gravel. The trailer was a little back loaded and walking some on the way home when I reached around 55 mph. While coming down a while, I coasted to about 55 mph and it began walking on me. I down shifted and applied the brakes to slow down. The truck took over everything and began applying the brakes itself in an anti-lock fashion. The traction control light on the dash came on. It took the sway out of the trailer. I assumed that it was the sway control system since I was not in a skid with my truck. However, there are no trailer brakes on this little trailer. Maybe my truck thought I was in a skid?

 

My brother works for Toyota Design in Michigan and this is what he told me:

"The Tacoma trailer sway control is a program in the brake computer that monitors the sway at the rear of the truck. I believe it uses the Vehicle Stability Control yaw sensor and basically uses the anti-lock brakes on the truck and the brakes on the trailer to bring the trailer under control if it starts to sway. I believe the 7-way connector needs to be plugged into the trailer for the sway control to be active, the system uses this to sense that a trailer is hooked up."

Since it is a program in the brake computer, it makes sense that the brakes would have to be engaged in order for the sway program to work.

 

Can I use the friction sway bar I already have for my 2018 along with the TSC?

 

Yes. Your friction sway bar will have no effect on the electronic systems the truck employees to maintain control. In fact will greatly reduce the chances of sway happening in the first place.
I would not rely on TSC as my only means of sway control when pulling larger/heavier trailers. Properly loading the trailer is the most important step (10 - 12% of the load weight on the tongue - i.e. if hauling a 1000 lbs. load there should be at least 100 lbs of downward force on the trailer tongue.

 

The system probably uses a small inertial sensor similar to the ones used in an inertial brake controller, except in place of sensing front-to-back movement (rapid braking), it is set to sense side-to-side movement. That's what Sway is, side-to-side movement of the trailer that tries to move the truck too.

Basically the system is "pushing" the manual override switch on the controller for you. OK, I'm far too lazy to manually crank a window down, but not quite so far gone that I can't push a button !!

 

Make this thread number 50 I am subscribed to (dammit, I told @ChadsPride the other day I was going on a thread diet too.......sorry Chad).

So wait, if I have my 7 pin connector plugged in for my tandem axle trailer, and I jam on the brakes causing the trailer to immediately jack knife, that sideways motion at the ass of the truck will activate the TSC system which in turn supplies current to my electronic trailer brakes, and controls which wheel on the truck receives the command to brake and the engine to reduce rpms???????????????

This makes it sound like you don't need a brake controller in a Tacoma. I can maybe see it activating the truck braking system to control which wheel receives the signal to brake, well, wait, no, I can't because I thought all the brakes were linked by the same hydraulic lines?

This thread needs some input. Inquiring minds need to know.

 

It uses Samurai Magic

 

Oh I'm getting to the bottom of this for sure! Ninjas or no Ninjas. Oh wait, you said Samurai.

 

https://youtu.be/SrcF_xhx6us