I have a 2008 GMC Envoy. This morning the engine coolant temp. gauge never moved, it stayed at cold while I was driving. The engine never got hot, the gauge just won't register. What do you think the problem is? Thank you.
many times the sending unit is the culprit. It could be a loose connection or a bad sender. I have seen where the stepper motor in the instrument cluster has stopped working also but the sender is the place to start.
Using a scanner and look at the coolant temperature. It should give you the digital temperature if the sender is working. If the computer does see the correct temperature then I would start looking the gauge unit. You should get a check engine code coming up if the computer doesn't see the temperature come up to normal operating temp after a while. (P0128)