Hey all, I just got around to hooking up the wiring for my new tachometer, and all wires are good except for the tach signal green wire. I had downloaded and read many posts here and other forums and they all say the tach signal is the black wire at pin9 on the OBDII port under fusebox. Simple enough,, BUT I do not have a wire at all at that pin. Can someone help me out? Do i need to find the black wire at the ECU? Where is the ECU located? thanks!

 

What kind of tach are you running?This is what im running
http://www.sw-performance.com/index....tails&p=114918
I can tell you what color and to what pin i have mine in.It's pluged into that fuse box thing right next to your left foot on the driver side.
Here is a pdf of what my wires go to and ill give the location of the pin #'s in the morning
http://www.sw-performance.com/upload...5065%20USL.PDF

 

I have a Sun Super Tach. I have installed them before and have always hooked into the coil, but on these cars we dont get that option. I really appreciate the help VIP_CAMO, all I need is that wire color and pin number for tach signal and I'm all set. I have two gray wires that are not listed on my XA wiring diagram, but no solid black.

 

Yup no problem..Ok so here is how mine is setup we should have the same wires xa/xb.pic's aswell to make it very easy to show you exactly were the wires are hidden.Ok here we go

The panel on the xb (xa)should be right there aswell.




That beige cream color type box is what you are looking for.


That blue wire im pretty sure is the 12volt power source



Ok now you see that white little plug that is at the bottom of the beige part.

pop it out to find the black wire






That is the black wire you need.It is the coil/tach signal

 

Thanks for the pics. Problem for me is that I dont have a black wire there or any wire at all. The only black wire i have has an orange stripe, but its at position 16. My XA is actually built in 2004 as a 2005 model, maybe they changed up the wiring? You think I could find that black wire elsewhere like the harness to the factory gauge cluster or maybe the ECU box??

 

Humm mine is a 05 model as well.picked it up sept of 04.So do you have that white plug/socket?/because that is were the obd scanner hooks up to also the scan gauge would go there so that wire you are looking for has to be on that plug.Also like you said you should be able to find it off the ecu just have to figure what wire is the tach signal.We usally have meets in san jose on wed nights let me see if a fellow xa shows up and ill take a look to see what i can find.Mine was done from a buddy who works at toyota and pulled it up on the computer so he knew were exactly everything was,maybe you can stop by toyota and ask them what wire is the tach signal?Ill see what i can do for you try to get some info

 

ok thanks, I appreciate it!! yeah I do have the white scanner port, I used to have a scangauge hooked up to it and it worked fine and showed RPMs. Its just weird that I dont have that black wire there. According to my diagram, the #1 pin on the ECU plug should be the tach signal, but i have no way to test that, and I'm kinda scared to try it, I dont wanna blow up my ECU. haha.

 

Yeah thats kinda weird thought the xb and xa are the same?I hear ya on that one dont want blow fuses or the ecu.Ill have to find me a diagram as well and compare it to the xa.All my wires are bunched and that black one is all by itself as you can see in the pic its either #1#8 or #16 im going to have to verify that now for future reference.

 

I just compared your pics with my plug and even my pin assignments are different, wires are not in the holes yours is. i have like two used then a blank one then two more used... man this is weird. When you get to the car meet Wednesday, see if anybody has an XA you can compare.

 

Well I think I got it figured out. I used the diagram to trace the wire at the ECU plug on the far right, last plug, pin 5, counting from top right to left. I will get the wire hooked up tomorrow and let you know how it goes.

 

Sounds good.Im def going to check out a xa hope it works out for you should have been the same dam scion!!lol..

 

So did not have any xa's show up so guess im on my own till i find one..Did it work?

 

Haven't had time to connect the wire yet...BUT... I compared the 04-05 XA diagram with the XB and its different. Totally different wire assignments coming off ECU. On the XA the ECU data plug wires and such are on the fourth plug...and on the third plug on the XB.. this is coming off the ECU box. So I guess thats good info for people...XA and XBs are not the same. They could also be different for the 06 models. The 04 XA diagram describes my DATA plug colors and ECU wire colors correctly.

 

oohh i see.Well hope ya get it worked out man.

 

ok, got it hooked up today and it works. woo :D