[QUOTE]Originally posted by modifry
[B]The blue/white speed signal wire leaves the speed sensor on the tranny and runs through connector C101 (behind driver's foot well, closest to the dead pedal) and then SOMEWHERE (over the rainbow??) it splices with another blue/white wire that goes to the ECM. The original blue/white wire continues to the speedometer.

The point is that putting the yellow box at the ECM will NOT adjust the speedometer, only the ECM.

I don't know what pisses off the ECM, but it could be any of these:[list=1][*]missing speed signal (good chance of this)
[*]sees an altered speed signal (I don't mean speed-corrected, I mean different voltage)
[*]sees a speed signal that is different than one it senses somewhere else (I don't know where, I'm guessing)[/list=1] Remember that because of the way the blue/white wire is T-tapped, the speedometer could work fine, but the signal to the ECM could be screwed up by an improperly installed yellow box. That may explain the CEL some people are getting. Then again, it's also possible that the yellow box does something to the signal that the ECM doesn't like, in which case you should only put the yellow box in the speedometer wire. But since all you want to change is the speedometer anyway, why fool with the ECM?

I do know that I've cut and spliced my wire and spent quite a while playing with a home-made "yellow box" and never once had the CEL come on. I believe where I spliced ONLY modifies the signal seen by the speedo and leaves the ECM alone, but I've not traced it out. But it doesn't matter - where I (and Sideways) spliced WORKS.

Here is the pic I sent to Sideways. The blue/white wire is the speed signal, the yellow one is +12v power. If you want the regulated power wire that feeds the speed sensor (instead of +12v), grab the yellow/blue wire in C101.


It is the blue wire with fine white stripe seen in the photo.

 

[QUOTE]Originally posted by slick rick
[B]No, the installation was done correctly.

 

Kust a comment, I haven't read the whole thread but i had a yellow box installed correctly and was still getting a cel traced it to the supplied plug with the yellowboc..reseated the wiring in the plug and it solved the problem...my cel would intermittently come on prior to that.

if you haven't you might check those

fltsfshr

 

I just installed the 4:77s this weekend, and the yellow box. Once again Thanks X-viper !! The gears are as on the edge as I want to be, but great , granted I am NA. I also agree that the shift beeper is a MUST have. I had it before the change. Now the shifts are really quick. Love the change so far but it definitelly changes the car. I have made it through 500 miles under 65 mph for break in. That's tough in this car. Today I LET a Z-4 pass me! I also installed the yellow box per X-viper THANK YOU again , per the transmission speed sensor , no CEl and no I didn't get dirty doing it, I am at a 18.25% correction and close to dead nuts. We have a measured mile in tenths with signs on I-78 I have been using for the last few days to fine tune. My tires are stock 02s and they are at 20,000 and real thin. That' why I suspect I am above the norm of 17% . I can't wait to lite up the rear tires and try to catch a few gears. So far I am at 4200 rpm in 6th at 65 MPH . Not bad considering I can ring it out till 9K!!!!!!!!!!! Hey I was real concerned with break in of the gears so I have frequently put my hand on the differential housing after driving for 15 -20 mins ( TRY THIS ) I dare you to hold your hand tightly against a stock diff for 1 minute. I tried this before and after to compare if I had excessive heat and a tight setup. This entire car is a heat sink due to the aluminum. Park it for an hour it' still hot! Time for a Diff fluid heat exchanger??

 

trich1687, NICE!
Just think what the diff would feel like if it had no fins? The fact that you can hold your hand on it for up to a minute means that things are looking good. When I put that point into my thread, I was only suggesting holding your hand on it for a few seconds.
As I said in my other thread, certainly, patching in the YB under the dash is far easier but as already been reported, not always a simple matter due to the large numbers of wires. Now that we have a detailed diagram, I'm sure we'll not see as many issues from that method.
Doing it under the car, has always been a guarantee of the proper wire selection. It is unmistakable which one to choose when doing it from the tranny.

 

[QUOTE]Originally posted by turbo_pwr
[B]Just wanted to update everybody.

 

I'm glad you gave us another way to do it. For those who may have the same fear as you about leaving the tranny wires exposed, they are electrical taped together to begin with. If you thoroughly taped them after the connections, they will not be exposed any more than they are stock. In fact, I taped them up far better than they started out being.

 

Yes my wire connections under the car better that new too and i haven't had any problems from weather water etc. but I do have a question. I saw Jenners name come up in here. I know he abandon his S2000 project. Does anyone know did ever solve his conflict between YB and his AEM setup?

ONe more comment on yellowboxes....if your a fanatic and want your speedo more exact than a mile marker count.. take a gps with you and set the scale to Km then do some runs. I found that to be a lot more accurate than mile markers, at least here in Florida anyway.

fltsfshr

hey xviper...you gettin frosty yet?

 

Hey, there is no need for such foul language here!
(Not yet!)

 

[QUOTE]Originally posted by Defender