1989 Jeep Cherokee TPS sensor voltage issue

[Landon18]

My TPS sensor is ready 0 volts with key on, when you unplug it, I get the 5 volts back, soon as you plug it back in the voltage disappears again and when I work throttle I see no change, I also tried a new TPS and just plugged it in to see if I got the same results and I did, any ideas?

 

[Unclewolverine]

Either two bad tps's, (common with non mopar, happened to me,) or it sounds like the signal wire back to the computer is grounded.

 

[lawsoncl]

Reading the signal wire back to the TCM with the TPS unplugged is pointless. If you're looking at the +5-volt wire though, then you have a problem. Set you meter for resistance and measure the TPS itself, while unplugged.

 

[Landon18]

No I tried to read the signal with everything plugged up but I couldn’t get the supply voltage or the input voltage so I thought about it and unplugged the connection and boom, had voltage on the tcm side, plugged it back in and immediately lost voltage, so I plugged my new OEM mopar TPS in and same exact thing, plug it in and lose supply voltage.

 

[Saudade]

I always have trouble getting the probes in far enough to make a good contact. Remember, these are weather tight connectors. Make sure the probe goes inside the seal and deep enough to reach the metal pin.

Also make sure the pins and sleeves are fully seated.

 

[Landon18]

It did, I was reading the connecter as I plugged it in several times and watched the supply voltage go to 0 each time I plugged it in, also if my tcm is bad would it cause this? Maybe the tps voltage input is shorted out in the TCM? Bc I’m also thinking my tcm is bad... so maybe my tcm on the tps input is shorted out causing the voltage to leave as soon as I plug it in?