Engine Hot AC/OFF indicator light came on

2010 Chevy Impala: hat should I expect to hear from a mechanic?

I would try to help you out here…but to say that you provided us with extremely little to go on would be an understatement.

SO…If you have an issue…please explain it to me so I can try to help you. What you provided is entirely inadequate. Let me know…I would like to help you if I can.


I’m not sure what else to say. The indicator light “Engine Hot, AC Off” came on. When that happens the tempature cauge remains at cold, no movement. Car runs perfectly well. There are no sounds or other disruptions. So, when I take it to a repair shop, what might they say the problem is? Is it an anti-freeze problem? Might the cauge be malfunctioning?

My best guess is that the engine’s temperature sensor is malfunctioning.
Since this car is apparently only 3 years old, it is possible that whatever the problem might be will be covered by warranty.

Before you take the car to an independent mechanic, check your warranty coverage.
If–for instance–the Powertrain Warranty is still in effect, you should go to the dealership for free repairs.

How many miles are on the car?

What is the state of overall maintenance? Not just oil changes but - generally, do you follow the owner’s manual service recommendations for everything? Specifically, has the cooling system ever been serviced? By the manual it might not have been required yet, depending on mileage, but say so. Have you checked the coolant level?

Did the light just come on at some point and stay on? Or did it come on once, or does it come on once in a while? Do you get heat inside of the cabin?

Stuff like that. Today’s cars are complicated so you need to be as descriptive as possible on the internet.

It has come on and off. It c0uld be off and then I drive awhile and it self-corrects. The car has 78,000. Required maintenance has been done. Coolant level is fine.

Need error codes read by Tech II scanner

For some reason the Engine Control Module is sensing an overtemp of the engine coolant. In this case the ECM program will disable A/C clutch engagement and turn the mentioned light “on”. The ECM probably also turns this light ‘on’ when you go to WOT.

A mechanic should check what the temperature is at the sensor location. It may be a problem with the cooling system or just a bad sensor. A bad sensor or an overheating engine would not necessarily set a DTC.

Hope this helps.