My TPS is at 1.45 V (but different engines, ECM, etc use differetn values).
I haven't figured out everything it effects, but it does effect TCC lock up. At low values,the TCC will disengage. If it's too low, the TCC will be disengaged while going down the highway with the cruise control on. I rasied my setting to prevent it from constantly engaging/disengaging.
It also effect power enrichment, but I haven't quite figured this one out completely. The ECM goes into PE at a certian value. If the TPS is set too low, it won't reach the high values.