Overactive VSC or TRAC - no throttle - help!

[bhap]

I have read a little bit about the "Andy Mod", but need a quick answer on which relay to pull to disable my VSC or TRAC (whichever one disable the throttle). At very low speeds or starting from a stop - especially uphill, I will lose throttle and not be able to move. I'd like to pull the right relay so I can drive until I have time to fix it or install the Andy Mod(2?). This is a stock, 2002 4Runner SR5 4WD. Any help is appreciated. Yes, I searched and couldn't find it.

Thanks

Bob

 

[nate22]

I'm having this exact problem too, Bob. Losing throttle is scary when trying to make a left turn in front of traffic! Have you had any luck getting this problem resolved on yours?

 

[phattyduck]

Try this:

http://www.toyota-4runner.org/3rd-gen-t4rs/155700-3rd-gen-yaw-calibration.html

-Charlie

 

[nate22]

Thanks for the suggestion and the link, Charlie. I've read through countless threads on this site looking for solutions to this issue, and I've come across the yaw sensor calibration before and dismissed it because it didn't seem like it would fix my problem.

I decided to give it a try anyway, since it's free and easy to do. I followed the instructions on the link, but.....no joy. I had to do it a second time because the first time I forgot to do the second part where you have to calibrate the deceleration zero point and my VSC lights both came right back on as soon as the vehicle began moving. So I did the complete process again and all my VSC lights went back to normal (off). I took it for a spin around the block and I had the same throttle stall/VSC engaging problem as before.

So while the calibration itself didn't fix my issue, it actually helped me learn how to disable my VSC/TRAC without triggering a CEL. The ironic thing is that when my VSC/TRAC lights are on on my dash, the throttle problem is completely gone. So how come it drives better without VSC/TRAC enabled? Is it a wheel speed sensor or throttle speed sensor or what? I don't know the answer, but at least my truck is driving okay now that those dash lights are back on full time.

Thanks again for the suggestion. I hope this helps others the same way it helped me.

-Nate

 

[phattyduck]

On the trucks with VSC/TRAC ('01-'02), the ECU has control of the throttle. Yes, there is a cable to the throttle body, but the throttle plate is (normally) driven by a motor, not the cable.

So, if the VSC/TRAC system thinks there is a problem, it will pull power. Your engine isn't misfiring or anything...

-Charlie

 

[nate22]

Correct, my engine isn't misfiring as far as I can tell. I'm just puzzled as to why my VSC/TRAC system is engaging under normal conditions when accelerating from a complete stop or very low low speed, at which point the power is cut from the throttle by the system. The system must be sensing slippage or something, but I'm not skidding or sliding or anything. I'm not mechanically savvy enough to know if wheel speed sensors or throttle position sensors or any other sensors could be causing this issue. I've owned 4 different 3rd Gens (1996, 1999, 2002 x2) and I haven't encountered this issue until this latest 2002. I took it to the dealership when this started happening years ago, they hooked it up to their diagnostics on a laptop and we did a road test and found no codes being thrown. Shortly after that, my CEL came on, thereby disabling the VSC/TRAC system, so my throttle issue went away. But if I clear the dash lights, the problem comes back, and it seems worse than before these days.

I don't know. It's puzzling, but I'm not frustrated yet because of forums like this with tons of experienced owners who know way more than I. Thanks again, Charlie.

-Nate

 

[TMP]

Andy Mod 2.0
The VSC/Trac is handy at times, but mostly not. This is an easy mod that will save your life!
https://www.yotatech.com/forums/f2/andymod-2-0-abs-remains-active-204623/

 

[jgue467]

....
So how come it drives better without VSC/TRAC enabled? ...

As an 8 year owner of an 01 with the same goodies yours has I'm gonna say there IS something wrong with your rig. Why do I say this? Mine has Never done what you describe yours of doing. I don't loose power when making turns or in the mud or on loose small rock/soil. Power is always there. The vsc has come to my aid more than once when I drove too fast down a dirty trail with S turns here and there.

I'd keep checking that system out per the FSM. Luck and enjoy the runner. :cowboy:

 

[ltsr]

[MENTION=116945]nate22[/MENTION] how are your tires?

 

[nate22]

Yeah, I'm pretty sure that there is something wrong somewhere on my truck, but the hard part is nailing down just what/where. Mechanical? Electronic? Both? It could be many different things, which is why I turned to this forum hoping others have had a similar problem and maybe a definitive solution. I'll keep plugging away with trial and error, but I don't want to sink too much money into it as I'm looking to trade up soon anyway.

My tires are great...Michelin's with about 30,000 miles on them but they still have lots of tread. And I my VSC/throttle problem was present even back the tires were brand new, so I doubt they are the culprit. Thank you all for the suggestions though. Keep 'em coming!

Nate