2007 Pontiac G-5 from time to time the temperature reading on the coolant will register ---F instead of a degree. Shortly thereafter then the check engine light will come on. Eventually the correct temperature reading will re-appear I have had it at the mechanic's twice but was unable to pinpont the problem other than it is possibly a sensor. This did not happen all winter but now with warmer weather it has started again. Of course when this does occur the cooling fan runs continuously. Any suggestions rather than just randomly replacing the sensors?
It sounds like you're getting an intermittent open circuit in the temp sensor. You should pull the codes to see it that is confirmed. The sensor is the most likely cause but it could be anything in the circuit including all related wiring or the PCM itself.
April, 11, 2011 AT 3:56 PM
I had the same thing happening to my g5, 2007, 2.2. I replaced the thermostat this weekend and so far so good. And it only took my son 5mins to change it. $21.00 @ Pep Boys
Hogie, hoganhill@hotmail. Com
April, 11, 2011 AT 4:04 PM
The thermostat is going to have NOTHING to do with the electrical gauge issue.