ok So I'll keep this short. Started going into limp mode. Checked codes and it showed output sensor so I replaced the output sensor and cleared codes and thought everything was good. Drove roughly 100 miles and then outta no where there it is....back.

In park it will set at 0 and not bounce or change.

Any gear the typical jumps are up to 20mph and sometime randomly jumps to almost 120.

The part that I don't get the most is once I start rolling...roughly 5mph the speedometer doesn't jump at all it has zero issues.

So to me it was noise or a short that happens when the motor turns from being put into gear.

But I have had someone watch the speedometer and I have lifted and wiggled the wires all over the place without any jumps while sitting in park.

Just looking for advice, a way to test the TCM or someone who had this issue.

oh also I supplied the TCM with power straight from the battery. I've also replaced the pigtails and wiring to the input and output sensors with no change. I'm holding a 13.65-13.75 in voltage. Has a good strong battery

video

https://youtu.be/htW7fkQ3xfI

Thanks Jeremy

 

The output speed sensor is the signal source for the speedo. From your description you changed it then this speedo jump cropped up. Sounds more like a bad sensor or connection at the sensor.

 

Old sensor was doing the exact same thing. Which is why the limp mode and why I replaced it.