Redneck1465

Hey guys I have a 94 Mustang that I converted to a 5.0L, 5spd, with a fox body throttle conversion on that I am trying to clear the rest of the codes out on. It is currently pulling a 122 code which is for the TPS and I have read pages and pages of posts on adjusting the TPS however when i try to pull voltage it is only at .268volts. Even when I try to turn the tps the voltage never seems to change. It is a brand new TPS. If you guys have any ideas please throw them my way.

88 orangepeel notch

Just to clarify, your probing the green wire and the black wire when testing ?

And which computer is in the car now ?

Redneck1465

Yes I am using the green and the black wire. The computer is a T4M0.

88 orangepeel notch

Wish I could help more, but I've never did this swap so hopefully someone with SN knowledge will chime in here soon.

Just from my digging around on the interweb, this was a working T4MO computer before the swap ?

Redneck1465

Yes the computer was working fine. It came out of a running 94 before I installed it in mine. Everything else works well I just am struggling trying to get the TPS to work right.

dawson1112

First thing to do is make sure your getting the correct referance voltage from the pcm by probing the red and green wire. Red is 5v ref green is ground. If you get 5v between the red and green wire then your problem is with the sensor itself. If you do not get 5v between red and green, then you need to check by probing red wire and a known good ground such as -battery terminal. If you get 5v between red wire and -terminal then the problem is with the ground circuit of the tps ( green wire ). If you dont get the 5v between red and negative terminal then the problem is in the referance circuit from the pcm.

Personally I would lean towards it being a bad ground circuit.

dawson1112

To continiue on,

If you get a good solid 5v ref from the pcm between the green and red wire, then the problem is with your sensor itself, either you just got unlucky and purchased a faulty sensor out of the box, or you need to use a 1/4 drill bit to mill out the slots on the sensor so you can adjust it enough to get it to .9v between green and black.

mjr46

check vref signal..........start there

Redneck1465

How do you check the vref signal?

dawson1112

5v ref as explained in post above. Red wire and any ground, with key on engine off should see 5v or very close depending on the quality of your volt meter.