2011 Regal gives "AC Off due to High Engine Temp" Message with no check engine codes or other hints

[I_N_J]

Hey all,

Recently my 2011 Regal with the 2.0T has been exhibiting some strange behaviors. Most days the car runs and drives just fine, but occasionally the temperature gauge will stop working. It'll stay pegged at 0 degrees (Or whatever the minimum is) and within a few minutes I'll get a ding and a message on the screen saying 'A/C off due to high engine temperature." In addition to this message, the radiator fans will begin to run at 100% full speed for the rest of my drive. Once I turn the car off, the radiator fans CONTINUE to run for a few minutes before eventually shutting off. Again, with the car off, the fans keep spinning.

The problem with this is that my engine temp is not too high. It's a false alarm, and I've confirmed it with a handheld thermometer gun as well as by literally being able to leave my hand on the valve cover and not even remotely getting burned.

So the engine temp is fine, but there's an issue somewhere with the temp sensor and/or computer.

I realize I could start replacing sensors, but I'm hoping that maybe someone else has had this experience before I just start replacing things.

Any suggestions?

 

[MelsRegal]

You would need an advanced scan tool to determine the issue. If it gets no temperature reading it will exhibit the symptoms you see to prevent engine damage. I would start with the tempersture sensor or it's wire harness.

 

[G-485906]

Hey all,

Recently my 2011 Regal with the 2.0T has been exhibiting some strange behaviors. Most days the car runs and drives just fine, but occasionally the temperature gauge will stop working. It'll stay pegged at 0 degrees (Or whatever the minimum is) and within a few minutes I'll get a ding and a message on the screen saying 'A/C off due to high engine temperature." In addition to this message, the radiator fans will begin to run at 100% full speed for the rest of my drive. Once I turn the car off, the radiator fans CONTINUE to run for a few minutes before eventually shutting off. Again, with the car off, the fans keep spinning.

The problem with this is that my engine temp is not too high. It's a false alarm, and I've confirmed it with a handheld thermometer gun as well as by literally being able to leave my hand on the valve cover and not even remotely getting burned.

So the engine temp is fine, but there's an issue somewhere with the temp sensor and/or computer.

I realize I could start replacing sensors, but I'm hoping that maybe someone else has had this experience before I just start replacing things.

Any suggestions?

I'm having the same problem with my 2013 Buick regal 2.0 turbo the same problem. I've replaced the temp. Control sensor and it's still doing the same thing. No one knows what's going on

 

[MelsRegal]

I'm having the same problem with my 2013 Buick regal 2.0 turbo the same problem. I've replaced the temp. Control sensor and it's still doing the same thing. No one knows what's going on

Who is no one? A dealer, a shop with scan tools?

 

[Mr.BunnySlippers]

I had this happen recently as well. I had leaking heater hoses for a little while that I hadn’t had time to replace yet. One night when I hadn’t topped off the coolant in too long this started happening.
It’s a pocket of air in you coolant system, which is MUCH hotter than the coolant itself. It makes the sensor spike super fast. I’d bet this throws the ECM into a panic. After keeping the coolant topped off for a few days this went away and hasn’t returned.

I would bet you have a small leak somewhere and an air pocket or two.
A really tricky leak I had years ago was a pinhole leak on the bottom of the overflow reservoir. That was a very difficult one to find. The rest are much more obvious.

Good luck.

 

[adaboy]

My 2011 with 146k miles just started giving me this message. I replaced temp sensor and thermostat so we will see if it comes back again.

 

[G-220704]

Replaced coolant sensor and harness pigtail. "A/C off" warning light still immediately comes on.

 

[G-85878]

2011 Regal 2.0 same issue. I replaced the Temperature sensor and pigtail. Thought I had fixed it. 4 miles down the road and false alarm came back in . “A/C off “ warning light came on and temperature gauge dropped to minimum. Fans running at high speed but the engine is not hot at all.

 

[MelsRegal]

2011 Regal 2.0 same issue. I replaced the Temperature sensor and pigtail. Thought I had fixed it. 4 miles down the road and false alarm came back in . “A/C off “ warning light came on and temperature gauge dropped to minimum. Fans running at high speed but the engine is not hot at all.

Thermostat stuck open

 

[G-364336]

My 2011 with 146k miles just started giving me this message. I replaced temp sensor and thermostat so we will see if it comes back again.

Did this come back? I have the same problem. Replaced the sensor. Fine for two days and then the message returned. Killed my battery since the fan would run for a while after shutting the car off. Replaced the battery. All fine for two days and then the problem returned again. Removed the new sensor, cleaned the connector with contact cleaner, disconnect the battery for 20 minutes to clear the computer. Then all was fine for two days and the problem has once again returned. I am at a loss!! Any suggestions?

 

[Cobryan001]

Did this come back? I have the same problem. Replaced the sensor. Fine for two days and then the message returned. Killed my battery since the fan would run for a while after shutting the car off. Replaced the battery. All fine for two days and then the problem returned again. Removed the new sensor, cleaned the connector with contact cleaner, disconnect the battery for 20 minutes to clear the computer. Then all was fine for two days and the problem has once again returned. I am at a loss!! Any suggestions?

I'm having similar issues with my 2017 regal going to attempt to replace the sensor tomorrow and go from there

 

[G-263083]

Our 2013 Chev Silverado did the same thing. It turns out the thermostat was opening too soon and the engine was running too cool, not too hot. I replaced the thermostat and never had the message again.