why does the ecm reset TPS voltage to zero after setting manually?

Question

replaced IAC and TPS,now idle is high and revs like a rev limiter ,i can set tps at .5 ,drive the car and ecm resets value to zero,Then trans starts to shift erractically

Answer 1

You have to use a hand pump to move the throttle opening, if it is impossible to set the TPS get another one . The one you have may be faulty