So, I finally got my car started on Megasquirt, and I recall that when I calibrated my throttle position, the values were flipped. Basically, as I put the throttle in, the TPS % went down. Calibrating swapped those values, but with a warning in tunerstudio.

I used the pinout from Symtechlabs for my 420A:



I also read on msextra that if more throttle drops the 'counts' down, then you have the TPS pot wired in backwards.

So, on to my question... does anyone know if the MS2 Extra Code/ ECU use 'counts' instead of TPS % as calibrated in Tunerstudio?

Basically, is the 'backwards' throttle signal acceptable to use once calibrated, or do I need the raw ADC counts to go in the proper direction as well?

Thanks,

-Evan

Sounds like you have the wires backwards. You should check it with a volt meter to confirm. When calibrating the sensor the AC voltage should increase as you push the throttle.

Thanks, I swapped vref and ground and all is well. The guys on the MsExtra forum said that though the code uses the calibrated value, I should switch it to avoid strange results.

Hopefully all is well now. I got the Stepper IAC working as well.