2ZR Turbo Yaris

[tmontague]

hmm weird, I would do as you stated and just run power directly to the VSS. Double check to make sure it is 12V but I would be surprised if it wasn't. If the VSS works with direct power then you know the power supply is the issue and you will have to work back from the sensor to see where the power is cut off.

If there is no power all the way back to the ECU then either you have a bad ECU or it has something to do with the piggyback or the wiring of the piggyback messing with the ECU. No way to know this other then try another known good ECU.

I just find it off that all of a sudden your ECU is potentially bad. I don;t believe in coincidences enough to believe that. I have a feeling it has something to do with the addition of the piggyback. You know more about the wiring and hook ups then I do in regards to the piggy back though so I'm not sure what your thoughts are on that.