ABS disable switch mod

I want to do the ABS disable switch mod to my '08 5 lug (no trac control or diff locker) and I'm trying to get an understanding of the system and what I need to do to make this mod work. I am loooking at these two diagrams (ABS w/o VSC and Stop light) My understanding is that the ABS pump is only activated when the ECU receives an input signal from the brake light switch. So by interrupting the input signal from the brake switch to ECU with a switch will disable the ABS pump and ECU from monitoring wheel speed and control of skid? I want to be 100% sure and receive input from others before I go cutting and splicing wires. TIA

Sorry if you see this a repost....thought maybe I'd have better chances of answers here in the tech sub-forum as well.

 

Bump Schmump

 

man i hope someone answers in reference to this method. I did the ground the blue/yellow wire mod and it blew a fuse. put a bigger fuse in and it worked but started smoking. hopefully your method works. haven't heard of that one yet. i've asked before but why can't we just switch off the power to it? put in a relay on the hot wire, and a switch to that maybe??

 

I think I'm on to something. Been thinking about this a lot (probably a lot more than I should have)

 

Page 185 of repair manual
ABS System Outline
This system controls the respective brake fluid pressure acting on the disc brake cylinders of the right front wheel, left front wheel and rear wheels when the brakes are applied in a panic stop so that the wheels do not lock. This results in improved directional stability and steerability during panic braking. especially off-road
1. Input Signals
(1) Speed senor signal
The speed of the wheels is detected and input.....to the ECU.
(2) Stop lamp SW signal
A signal is input to terminal (B) 14 of the skid control ECU with actuator when the brake pedal is depressed.
2. System Operation
During sudden braking the skid control ECU w. actuator has signals input from each sensor, which controls the current to the solenoid inside the actuator and lets the hydraulic pressure acting on each wheel cylinder escape to the reservoir........the rest is pretty much how the actuator adjust to wheel difference.



So, doesn't it make sense that by interrupting the brake light switch signal to the ABS ECU with a switch will disable the ABS from reacting when braking off-road. I just need to know that is correct and that it won't affect anything else, such as power assist. To me this makes sense, I don't see anything else that inputs to the ABS ECU that the brakes are applied and there is need for ABS (so they think ). Please any input or help would be greatly appreciated, I know there are quite a few of us out there (w/o TRAC or VSC) that would love to have this mod. TIA

 

Sounds right to me, and doesn't sound like it would affect anything else. I'm tempted to just give it a shot. Its not like i haven't already melted wires and blown fuses. If this works, I'll mail you a beer or something. Good thinking... and I don't expect much feedback because i doubt its been tried this way. i'm with ya. maybe this afternoon....

 

based on the diagrams the only thing i'm fuzzy about is the deceleration sensor.... what does that do that the speed sensors don't do. as long as that thing isn't a hangup, i'm in.

 

i would love to know cuz i hate the abs bullshit

 

Isn't the deceleration sensor to keep the RPMs up between gear shifting?

 

Nope! Bad guess and wrong application! Sorry!

Here is a link to a good description of ABS systems and how components work........
http://www.autoshop101.com/forms/brake09.pdf

 

I have an '09 TRD Sport, which does have VSC, etc. Last weekend I pulled the 2 fuses marked "ABS 1" and "ABS 2" (50A/30A) to see what happens. I get the ABS light coming on AND the VSC (squiggly line and car) light coming on, regardless of whether I pull one or both fuses. Earlier years may not have 2 fuses I hear.

I would suppose that putting a switch on those 2 fuses would turn the ABS off, but I don't know how to turn ONLY the ABS off.

 

well i don't have trac or vsc so no worries about that. I still want to hear about the brake light switch wire.........

 

Hey man if you are willing to try it out, I can help you out and point you in the direction of doing it clean and right, the way I'm gonna do it. (I'm just waiting on my race covered toggle switch to come in). This way seems a lot more promising than the others and less likely to blow or melt anything. As long as the correct gauge size wire is used (same size from switch to ABS ECU) I really think it would work out fine. Not to be whatever but yah the first I've heard of this method on any forum was by me. Let me know if you want to try it out and if you want some help. I don't drink but I will drink that beer if it works(no domestics please). A joint is right up my alley tho

The deceleration sensor is used in 4WD trucks, to determine deceleration rate since in 4WD braking characteristics are different from those of a 2WD. If you look in the the diagram, the are (*1) next to the wires of the circuit between the deceleration sensor and the ABS ECU, meaning that it applies only to 4WD. The deceleration sensor does not apply to my system.

There is a correct mod for your truck to only disable the ABS. In your model(w/ VSC or locking diff), when in 4Lo (i believe it's 4Lo) the ABS is disabled(this is stock) and in only 4Lo. So the method I have seen is they bypass the signal to the ABS ECU letting it know the trans is in 4Lo and it will keep from activating. You should be able to find the mod for your model on all the forums, try searching.....locking diff mod, or andy's mod or even abs disable but disregard the ones that say anything about w/o VSC or locking diff(most likely just another one of my threads). Good luck!

 

http://www.customtacos.com/tech/index.php?article=10
Check that out...should point you in the right direction. There are step by steps out there for the later models, you just gotta find them.

 

Well, I did it!!! and it works great!!! now should I make another thread to show the install/write up or should I just add it to this thread? Pics will be included.....

 

Rodstone, You could edit your 1st post and put it all nice and neat up at the top.

 

ok here's the the problem im having. the car is a 2009 tacoma, diff lock/vsc/rsca blah blah blah. i just want to know which freakin wire(s) it is to disable the abs. what colors, where are they, what row, easy way for me to find it or them.