*Write Up* Installing the Yellow Box Speedo Calibrator

[Scuba]

Shift points are based on RPM's not speed. You have a VSS ? You'll be fine

this is an awesome writeup. ive done alot of internet surfing and youve got the most complete install instructions anywhere. i learned that my truck (96 4runner with abs) does not have VSS. the ABS trucks ive read take the signal from the wheel sensors and feed that to the abs computer. the the abs computer interoperates that and spits out a signal that runs to the dash gauges and then to the ECU.

Really ?
Even still, you could still splice into the signal wire from the ECM to the combo meter..

[YotaFun]

Really ?
Even still, you could still splice into the signal wire from the ECM to the combo meter..

.... I don't know about that, might mess with the ABS operation

[Scuba]

As suggested by a member of another forum, I added in a fuse. 2.5A
Also, while I was in there, per the instructions I wrapped the yellow box in some very high tech stuff in order to keep the dust out of yellow box.

[img width=600 height=800]http://i11.photobucket.com/albums/a168/Sycosurfer150/Truck/Speedo%20Calibrator%20Install/IMG_0993.jpg[/img]

[corax]

Really ?
Even still, you could still splice into the signal wire from the ECM to the combo meter..

.... I don't know about that, might mess with the ABS operation

Not if it's only intercepting the signal to the cluster - - if the signal goes into the cluster and then branches off to other modules, then you might have problems. But really, even putting bigger tires on an ABS vehicle will have an effect . . .

[YotaFun]

I realized that, but I figured in the wonderful world of electronics if the resistance wasn't right or something that it would set off an ABS code.

[04 Rocko Taco]

Can we not just take it to a speedo shop to have them calibrate it if you dont have the VSS or if you are afraid it will mess with your ABS?

[Crinale]

haha, ya i wonder how bad my speedo is gonna be now <.<

[Scuba]

Can we not just take it to a speedo shop to have them calibrate it if you dont have the VSS or if you are afraid it will mess with your ABS?

Well, the trucks have a gear inside the tail housing of the transmission and you can swap out the gears but you probably won't get it perfect. I could have swapped gears but my difference was too large for the gears to make a good difference.
If you have an electric VSS, how would you calibrate it without the box ? This yellow box does math every single milisecond to change the signal going to the ECM.

I still don't think the other "abs" concerns in this thread are valid, but I didn't feel like arguing.

[troyboy162]

im searching to figure it out. so far it looks like a square wave that its made by the vss sensor or the abs computer. this is the signal path i read about

1. wheel sensor to the
2. abs computer to the
3. gauges to the
4. ecu/ecm

so cheap basterd that im am...trying to figure out if i can use any old speedo calibrator and splice it into behind the dash.

it got me thinking because almost all these company's sell the same unit for lots of verticals and the difference is the cable harness. and if ever unit is basically the same then there are alot of used motorcycle units available for cheap since those guys seem all about them.

so if you splice up stream from the gauges...your abs gets raw wheel spin data and everything else gets actual speed data. i would think thats the best scenario for all the systems involved but i could be wrong on alot of this stuff.

[Scuba]

Well I mean, if altering the signal from the VSS to correct it to where it should be, how does that hurt the ABS ? I guess I'm just not sure where your guys' fears are coming from.