"Engine Hot AC OFF" on DIC. Temp gauge sweeps then stays at pointing to far left.

[Bill S.]

Hi

Got the message "ENGINE HOT A/C OFF" message today after having driven the V for about ten miles. Tried turning it off and on a couple times. No change. The temp gauge needle at start up does the usual sweep, then parks at the stooped position, pointing to the left. Opened the hood. It was not unusually hot and the Radiator fluid was fine. No leaks. . Parked it for the day. Came back started it up and immediately got the same message. Just drove it home. Anyone familiar with the cause or fix for this ?

Bill

 

[cubby558]

Bill,

There may be some posts on here, but if I remember correctly, the thermostat being replaced will most likely correct this. I never had this problem when I had my V, but I remember others having this and they replaced the thermostat and that fixed the problem.

Good luck.

 

[xlrlist01]

Hi

Got the message "ENGINE HOT A/C OFF" message today after having driven the V for about ten miles. Tried turning it off and on a couple times. No change. The temp gauge needle at start up does the usual sweep, then parks at the stooped position, pointing to the left. Opened the hood. It was not unusually hot and the Radiator fluid was fine. No leaks. . Parked it for the day. Came back started it up and immediately got the same message. Just drove it home. Anyone familiar with the cause or fix for this ?

Bill

This has been discussed before, a long time ago. IIRC the message is mis-leading and there is an electrical problem, probably minor. From memory it goes something like this. The message says 'hot' because the ECM does not know what temperature the engine is, but does know there is a sensor fault. The message says 'hot' because Cadillac figured drivers would pay attention to that, more than a more accurate message which might have said 'engine temperature unknown'. Others have reported this message and the thermostat has been fine, the temperature sensor or sensor wiring has been defective. The X will behave as if it over-heating, even though it isn't, but the ECM does not know that.

HTHs.

 

[ScottH]

New thermostat fixed mine.

 

[Arandich]

Hi

Got the message "ENGINE HOT A/C OFF" message today after having driven the V for about ten miles. Tried turning it off and on a couple times. No change. The temp gauge needle at start up does the usual sweep, then parks at the stooped position, pointing to the left. Opened the hood. It was not unusually hot and the Radiator fluid was fine. No leaks. . Parked it for the day. Came back started it up and immediately got the same message. Just drove it home. Anyone familiar with the cause or fix for this ?

Bill

Bill
As others have reported this is often fixed by thermostat replacement or engine temperature sensor but not always. It occurs because your engine temperature is actually colder than what is expected based on time, engine speed, etc. calculated by the ECU. The mismatch throws the code. Your car isn’t overheating but is too cold. If it is your thermostat it usually sticks open so can won’t overheat. It can be sporadic because for example, if you travel at very slow speed and let the engine warm up properly it matches the expected calculated temperature Alternatively, if you drive very fast quickly it will throw the code because the mismatch. You may notice the code always occurs the same distance from home if you always drive the same route and speed. If no fixes work, e.g., thermostat and engine temp sensor you only have one recourse - as done by my Cadillac dealer. They bought an aftermarket tuning kit and completely deleted the error codes associated with this problem. Fixed mine. Your temperature gauge works fine and the only problem would be if your car actually overheated. Thousands of GM cars have this problem and GM refuses to address the issue.

 

[pure zen]

Quote: "Thousands of GM cars have this problem and GM refuses to address the issue."
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Truthful and very sad to agree with. They, and other manufacturers,,,,only care about bottom-line profits.

 

[TXNXLR]

I’ll add that replacing the thermostat fixed our ”Engine Hot - A/C OFF” issue as well.

We “limped“ for a while, letting the engine warm up for over a minute before moving the V and that helped, but it obviously wasn’t the cure. The thermostat was the cure.

The other thing I found odd was that the ECU didn’t reset the fault after powering off and the engine being stone cold. Having to breakout the Tech 2 to reset it each time was a pain.