check engine light P0128

[JFR]

Aveo LS 2006 42,000 miles. Check engine light (while I was driving temp gauge went to
0, then came back to mid scale, normal again).
I used a scanner and found only a P0128 code. It said open thermostat, or sensor. I changed the thermostat and housing. I was lucky, got a new metal one. Now to change the sensor. Anyone else have this code?
I searched the forum, but could not find any p0128 or any p0 codes.

frank

[JDM_GUY]

I had that problems once or twice, I replaced the thermostat and coolant temp sensor that is at the back of the engine under the throttle body.