turn off traction control?

[Zaraspook]

Is there any way to turn off traction control or any aftermarket switch that can be installed to do it? Ever so often trying to get out into traffice quickly it kicks in and hinders things instead of helping. It will kick in even if there hasn't been any loss of traction.

'04 4x4 V6

thanks

Z

 

[CMiYC]

It will kick in even if there hasn't been any loss of traction.

Er... that's what you think. If you felt the truck lose traction, it wouldn't be working. The manual clearly says you can not permanently disable the traction control.

 

[ToolmanJohn]

Is there any way to turn off traction control or any aftermarket switch that can be installed to do it? Ever so often trying to get out into traffice quickly it kicks in and hinders things instead of helping. It will kick in even if there hasn't been any loss of traction.

'04 4x4 V6

thanks

Z

1) Leaving it in 4WD helps a LOT. Although there is the drawback of fuel consumption (slight increase). Distributing engine torque to all 4 wheels improves the grip on the road. I can still trigger it if I hammer on the gas, but only when I was experimenting with the limits of the system. Be warned, you can overwhelm the system and slip. Rubber is rubber, once traction is gone, it's gone.

2) It can probably be shut off, but someone will have to decipher the electrical schematic to find out what control wire needs to be shunted for it. Either the anti-lock brake system will have to be deactivated, or some way of tricking the computer into thinking there is no problem.

3) If it has turned on, then you have experianced a loss of traction. This usually happens on wet roads, or where there is sand in a turn at a stop. You may not think your rear wheel has slipped, but if traction controal has turned on then the truck detected wheel spin , however slight, and is attemting to stop it with the appropriate brake.

 

[dcampen]

Ever so often trying to get out into traffice quickly it kicks in and hinders things instead of helping.

Which system are you talking about, VSC or TRAC? I suspect that you are talking about VSC. TRAC is the traction control system, VSC is intended to compensate for over and under steer. On 4WD models, VSC is deactivated when you lock the center differential. Have you considered that in the instances where VSC activated on you that if it hadn't you might have ended up spinning out and going into the ditch?

 

[ToolmanJohn]

I think it's TRAC, not VSC.

Who would drive with the center differential locked on the road?? It would be kind of defeatist, since normally the torsen differential will distribute power front to back as needed.

The diff would only be manually locked where power transfer would be benefitial at a locked 50/50, such as sand, loose terrain, and driving slowly over rough terrain.

And VSC is for detecting the truck traveling in a direction not intended by the driver, such as taking a turn on an exit ramp a bit to fast, and suddenly loosing traction, the yaw sensors will detect this, comparing it to steering input, and try and counter a skid with selectively applying the brake on the correct wheel. With that said, you can crash your truck. VSC will not save your ass if there is no traction to be had. Don't travel faster than road conditions permit.

Wait until the winter, find a nice flat parking lot with plenty of snow, and find the limits of VSC. I did this last winter to learn the capabilities of the truck. Your tire choice makes a huge difference. That's why this winter I am going to get another set of wheels mounted with real snow tires. I am looking for better braking performance. The 4 wheel drive system is awesome for get up and go, but will NOT help you slow it down again.

 

[Vortec4800]

I was thinking about this too, which I would want to disable traction control after I get bigger tires and need to use my spare. I'd imagine traction control will see one wheel spinning more than the others and lose its mind. I think if you just find the fuse that goes to the traction control you can probably put a switch on it, or in my case just remove the fuse while I have the spare on (as short as possible).

When I did a BMW performance driving school they had a bunch of 330's that come with traction control standard. To do the driving school, they had two switches in the car that completly disable traction control and dsp, and another switch to kill the abs. The instructor said it basically just kills the fuse disabling the system.

 

[dcampen]

Who would drive with the center differential locked on the road?? It would be kind of defeatist, since normally the torsen differential will distribute power front to back as needed.

The diff would only be manually locked where power transfer would be benefitial at a locked 50/50, such as sand, loose terrain, and driving slowly over rough terrain.

Yes, isn't that obvious? Except that when the center diff is locked the front to rear power split can be any value. It is when the diff is unlocked that you are limited to a particular value of front to back power split.

The point is that this means you might be able to spoof the ECU into disabling VSC by sending it the signal to lock the center differential while at the same time interrupting the transmission path of the signal from the ECU that causes the center diff to lock. I am assuming that locking of the center diff is mediated by the ECU.

 

[dcampen]

I think if you just find the fuse that goes to the traction control you can probably put a switch on it,

So you think that there is likely to be a separate computer for the TRAC/VSC/ABS system?

 

[ToolmanJohn]

TRAC Mtr Relay perhaps

There is a relay in the Engine Bay relay Box, it is labeled Trac MTR Relay. I wondor if pulling this will shut down TRAC control. It's in the wiring diagrams. It seems there are also relays for VSC , yaw sensors, and Skid control.

 

[Vortec4800]

So you think that there is likely to be a separate computer for the TRAC/VSC/ABS system?

Not necessarily a seperate computer, but a seperate fuse for each that will disable each system. That way if one system has a problem and shorts a fuse, you still have the other systems running. I haven't looked, but I would imagine that's how it works.

 

[ToolmanJohn]

Except that when the center diff is locked the front to rear power split can be any value. It is when the diff is unlocked that you are limited to a particular value of front to back power split.

I am assuming that locking of the center diff is mediated by the ECU.

Actually the opposite of what you are saying is true.

The center differential is a Torsen Type 3, the most advanced yet. Normally, in multi-mode 4WD, it AUTOMATICALLY does it's thing (fully mechanical, no electronic involvement in torque bias front to back). It is always ON and splits torque automatically (within limits) in 4WD mode.

If the center differential lock button is pushed, torque bias is LOCKED 50/50 front to back. No more automatic torque bias.

http://www.off-road.com/toyota/models/2003/4runner/news1/

"4Runner is the world’s first use of a Torsen3 sensing type limited-slip center differential in a mid-size SUV transfer case. The Multi-Mode 4WD feature is an open center differential with locking capability that provides a full-time 4WD system with the ability to select 2WD mode. The 4WD mode may be used in normal driving conditions on all types of roads from dry, hard surface roads, such as pavement, to wet or snow-covered roads. Driving with the Multi-Mode’s 4WD system engaged provides the driver with a more sure-footed feel because power is applied to all four wheels, improving traction.

The new torque-sensing feature allows the torque split mid-point to be more biased toward the rear, sending more torque to the rear wheels, providing better stability control whether the driver is accelerating at high or low speeds. The static rear-drive bias favors stable tracking on- or off-road, decelerating or accelerating. The Torsen™ type sensing provides three dynamic torque split ratios, depending on the available traction on the vehicle at the time. A static torque split favors the rear with a 40/60 percent front-to-rear split. When the front wheels slip, up to 70 percent of the split ratio goes to the rear wheels. When the rear wheels slip, up to 53 percent of the split is applied to the front wheels. "

Still don't believe it?

http://www.toyota.com/vehicles/2004/4runner/key_features/tech_module.html

Click on 3-D tech Demo, torsen center differential

 

[ToolmanJohn]

Is there any way to turn off traction control or any aftermarket switch that can be installed to do it? Ever so often trying to get out into traffice quickly it kicks in and hinders things instead of helping. It will kick in even if there hasn't been any loss of traction.

'04 4x4 V6

thanks

Z

Zaraspook, try this if you dare. Pull the pink TRC MTR relay. See if you can burn some rubber. My guess is it won't allow TRAC to be active any longer. Perhaps it will display on the gauge cluster as a VSC failure, amybe even generate an error code? Who knows, but it does control the TRAC system.

 

[Zaraspook]

Thanks for all the ideas. Just for those who are wondering, I am talking about a situation where I was pulling out of a parking lot onto the street on dry pavement so the truck was in a slight turn while I was accellerating hard get out into the flow of traffic. There was no wheel squeal before the traction control kicked in. Just as I was expecting to really take off it kicked in an accelleration went from nice and speedy to something akin to running on half your cylinders.

I have also noticed that some kind of braking kicks in if you are trying to climb even a small curb and let off before you make it and the vehicle starts going backwards. This is only a slight problem getting into my garage where the ground has shifted and there is a little lip to climb but I don't want to give it to much gas since there's no landing room in the garage for a massive lurch forward.


I'm still not sure whether it's VSC or TRAC that's kicking in.

Z

 

[kglueck]

If an alarm beeped when it did its thing when you made the turn out of the parking lot (great sentence, eh?), then it was the VSC. If it just clicked and whirred, then it was TRAC. Sometimes it'll happen when you leave a parking lot like that if there's a lot sharp dip, what actually is happening is one of the tires is momentarily in the air (only has to be there for a short time) and the vehicle senses that the tire is spinning faster than the others, so TRAC kicks in to redistribute power to the wheels with connection to the road. There's a place near my church that I can make it happen every time w/o trying... In all, I'd say that I'd rather have that happen every once in a while and still have the vehicle stability control and traction control operating normally. It's come in very handy for me at times....

Kevin

 

[toybox]

Do the 4x4's even have TRAC?

I don't think we do. 4wd's only get the VSC and TRAC is logically only for vehicles without 4wd.

 

[kglueck]

well...I should have said...in my 2wd 4r that I used to have I could make it happen....haven't been through there in my 4wd yet. As for it, well, dunno. haven't heard my 4x4 click and whirr yet, so...

as for whether 4x4's have it. the brochure says this in the footnote about VSC + TRAC:

4-Wheel Traction Control (TRAC) in 4WD only. Rear-wheel Traction Control (TRAC) in 2WD mode.

 

[dcampen]

If the center differential lock button is pushed, torque bias is LOCKED 50/50 front to back. No more automatic torque bias.

So you are saying that with the center diff locked and if TRAC was disabled then if the front wheels were on a frictionless surface no torque would go to the rear wheels. I believe that it would be just the opposite; 100% of the (non zero) torque would be delivered to the rear wheels.

 

[dcampen]

Do the 4x4's even have TRAC?

I don't think we do. 4wd's only get the VSC and TRAC is logically only for vehicles without 4wd.

Yes, the 4X4s have TRAC. TRAC is needed to compensate for not having locking front and rear differentials.

 

[ToolmanJohn]

On 4WD models it's called A-TRAC

Technically, Active Traction Control

"All 4Runners are equipped with standard Vehicle Skid Control (VSC) with traction control (TRAC) on 2WD models and active traction control (A-TRAC) on all 4WD grades. VSC utilizes the braking system to help the driver maintain control in adverse driving conditions. The system’s TRAC feature helps reduce tire slippage during acceleration. "

Everyone just calls it TRAC, for traction control system.


"Except that when the center diff is locked the front to rear power split can be any value. It is when the diff is unlocked that you are limited to a particular value of front to back power split."

LOCKING the center differential LOCKS the torque bias, 50% to the front axle, 50% to the rear. It is not possible to get 100% of the available torque to any axle IN 4WD MODE. Unlocked, the differential can send UP TO 70% to the rear axle, or UP TO 53% to the front axle.

HOWEVER if you want 100% sent to the rear, drive in 2WD MODE. That's the only way to get it. You can't get 100% to an axle in 4WD mode. Unless you want to modify what Toyota had built. It is on their website. Second link in my last post. It is on MANY write ups. Online search for 2003 4runner 4WD System.

 

[dcampen]

LOCKING the center differential LOCKS the torque bias, 50% to the front axle, 50% to the rear.

Where you get this idea? Locking the center differential disables the differential making it the equivalent of a solid piece of steel.

It is not possible to get 100% of the available torque to any axle IN 4WD MODE.

Yes you can. Assuming that my description of the effect of locking the center differential is correct then I described an example in my previous post. With the center diff locked and the front tires on a frictionless surface no torque will go to the front wheels but a lot of torque (100% of a non zero value) will go to the rear wheels.

Unlocked, the differential can send UP TO 70% to the rear axle, or UP TO 53% to the front axle.

Yes, this I agree with.