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George H.
George H., ASE Certified Technician
Category: Chevy
Satisfied Customers: 18765
Experience:  GM Tech ASE Master Tech 15+ years
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2005 coolant temp gauge would not go back to the

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2005 coolant temp gauge would not go back to the off position when i shut off the car(would stay at whatever temp it was when the car was on)mentioned it to the dealership when i had my 51,000 mile maintenancetranny and coolant flush)..was told that the gauge was bad and i needed to replace the parts cluster... 1-2 weeks later coolant temp gauge would rise all the up just about to the red and then cool down to about 190 or so until a red light then would shoot back up all the way and go back down when i resumed driving . the high coolant temp light came on today ...would this still be a symptom of a bad gauge or something else??

Hello I will help you with your question,


The stepper motor for the gauge has failed and you will need to replace the cluster.


GM has issued this TSB on this problem, this is a TSB about noise but note the line that refers to replacing the cluster for a functionality problem. Of course I would check the coolant level just to be sure.


Click here


Let me know what I can do to help you with this


Thank you



Customer: replied 7 years ago.
the coolant level seemed to be fine in the radiator but im not sure about the correct level in the expansion tank. would the sensor that causes the high coolant temp light to come on reading the gauge or would it reading from the actual temp of coolant . i was just a little concerned that the sensor that would cause that light would be reading off of the thermostat or the coolant not the gauge

The light would come on if the gauge went to the extreme limit so if the radiator is full you are looking at replacing the cluster. The cluster would have to be programmed with the mileage so it needs to be done by a shop with a Tech 2 scantool.


The IPC displays the engine coolant temperature as determined by the PCM. The IPC receives a class 2 message from the PCM indicating the engine coolant temperature. The engine coolant temperature gage defaults to 60°C (140°F) or below if:

  • The PCM detects a malfunction in the engine coolant temperature sensor circuit.
  • The IPC detects a loss of class 2 communications with the PCM.

So a high reading is not a communication problem


The track record for these clusters is not good so the gauge motor is your problem.



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