2008 Saturn Aura Temp Erratic

[Fishinguy40]

I posted earlier but no response. Have an update so hopefully someone can answer my questions.

Daughter's car has been having issues with erratic temp gauge. Had this last January. she had a friend change T-stat and temp sensor but no fix. I then went through all the connections. Couldn't find anything wrong but the problem went away for about 8 months and then started again.

This morning she had trouble starting and said she could smell gas (very rich mixture?). I picked the car up from her work and drove to parts store. Codes were P0116 and P0117. I also noticed that the temp gauge never moved off of cold even though I had plenty of hot air blowing out the heater vrents.

Got home and per TSB 09-06-03-004D I put dielectric grease on the temp sensor pins and ECM pins. Started car and temp gauge read normal. Engine light also went out. Did the gauge start reading because the ECM was powered down/reset or did I do something making/breaking the connections? I know powering down the ECM cleared the codes but what about the gauge all of a sudden working?

I'm curious if the dielectric grease is the fix or not. If this doesn't work, I will have to defer to a professional (Airjer).

[Jeremy airjer W]

On the older Saturn s series the fix for the coolant temp sensor issues was a new temp sensor and a new pigtail (the connector). I have not run into any coolant temp pigtail issues on an ecotech or the v-6 but it is not impossible. IMO what DIY the trick was probably unplugging and plugging in the connector. In theory the connector could be "wiggled" (I know this isnot a ford, but whatever works) while watching the scan tool data or using a volt meter and a pair of JR Jumpers to tap into the wires. If there is any drop out than I would have to suspect the connector.

The wiggle test is used pretty frequently on older GM MAF sensor connectors. When there bad they will make the engine do all kinds of neat things when you wiggle them.