[Joemoseley]

Hey guys, so my 08 will be going down the road running at normal operating temperature, and all of a sudden the temp gauge in the dash will slowly drop below C, and stay there for awhile, and then come back up (sometimes not all the way at first). It only does this once in a while, so I changed the thermostat/housing a few months ago, and I am having the same problem. Only now it has thrown a p0128 code for coolant temperature, any thoughts? How many coolant temp sensors are on this engine? And which ones give info to the ecu or gauge in dash? Thanks!

 

[zetecDon]

Moved to "General Technical Chat".

 

[freemind]

Check the Cylinder Head temperature(CHT)sending unit and the pigtail for any cracked or, pulled(bare)wires.

Post results

 

[Joemoseley]

Does the CHT sender only feed the temp gauge in the dash? Or the ecu as well

 

[sailor]

Both, AFAIK the gauge is fed off the PCM.

Some of your model have a sensor by the thermostat as well, and I'm actually not sure of it's function since not all use it.

 

[Joemoseley]

Ah okay, I am going to Check wiring and replace this sensor and see what happens thank you guys!