Video of erratic temperature gauge tell me what's happening ***video***

[mtndew568]

watch the video of my temp gauge going all over the place.
I have replaced water pump, flushed radiator 3 times and also replaceed the temp sending unit in the block.
At the end of the video I am just cycleing the ignition to show how much variation there is.
I am leaning toward new ecm.
I need advice.

http://www.youtube.com/watch?v=FSGUHmpF4dQ

[peeweewasblue]

I have never seen that before so I broke out the book. That gauge has 4 inputs, BAT, ING, Ground, and UART data line. All 4 connections go to a solid state chip that feeds the gauge. The actual information is on the UART data line. The UART data line comes from the Powertrain Control Module (PCM). Since I saw the Driver Information Center (DIC) say engine hot I would assume that the gauge is showing the information that is being sent to it from the PCM on the UART line. You did not say what your trouble codes are, since the check engine light is on I know you have some codes. Also I would check to make sure that your grounds are good. Since you said that you have replaced the sending unit the next thing in line is the PCM. Good luck