I am having some issues... I have 99 trans am that has been setting around for about 2 years. Anyways just got new motor in and and now I.have no tps or map signal voltage goin to either... I checked on snap on scanner and both reading nothing of course...

 

They each have a gray wire going to them that is a 5 volt reference wire. Check that for 5 volts. I think that's how the 5 volt reference signal works but not certain.

 

Check it as close to the PCM as possible to rule out a bad wire. If you have the 5V ref. check the ground as well. If ground is good and no 5V, the step down transformer is probably bad on the board and you will probably need a new box.

Rob

 

Checked at pcm had no on tps or map 5 v signal.... pulled intake found my map wires where melted togeather shorten out both ref signals... new map wire now all fixed.... sweet.... so one thing learn if don't have 5v signal doesn't mean comp is bad look for shorts in wiring

 

Cause it shuts signal down evidently when ecu detects problem