Coolant temperature gauge on dash showing wrong temperature while ECT reads correctly.

It also has never overheated

The ac is also working fine with hot air blowing out.

Disconnect the battery and hold the two leads together for 10 seconds. Re-connect and see if that helps. Maybe you need to recalibrate the instrument cluster. How that is done, I don't know.

Drunken Elvis said:

Disconnect the battery and hold the two leads together for 10 seconds. Re-connect and see if that helps. Maybe you need to recalibrate the instrument cluster. How that is done, I don't know.

Click to expand...

So a reboot/ capacitor discharge?

Drunken Elvis said:

Disconnect the battery and hold the two leads together for 10 seconds. Re-connect and see if that helps. Maybe you need to recalibrate the instrument cluster. How that is done, I don't know.

Click to expand...

Does this model have a second battery?

I have not seen a 2012 with two batteries unless it's hybrid. Look in your owner's manual and trunk for a second battery.

Now that I see it, the only way I can think of to correct it is to take the IPC out and take the faceplate off.

You might be able to get away with just rotating the needle clockwise to the C, but if not, then you'll need to pop the needle off the shaft and then reinstall it.

There is a bit of trim to remove to get to the IPC, but once you can access it, it's pretty easy to remove: 4 screws and 1 plug.

Here is the thread where I share swapping my IPC from white to red LEDs.

Gen7 Instrument Cluster Innards | Chevrolet Malibu Forums (chevymalibuforum.com)

Whats the error code on your check engine light? I wonder if you have a bad temperature sensor. I know you said it reads correctly, but my car has two temp sensors and the one might be reading correctly and thats what you are seeing with the reader, but the cluster might be pulling from the other one. Just a guess in case its not an issue with the needle.

I will wager that it's an issue with the needle, or even more the gauge's little motor, that allows it to swing past the range markings.

When it's off, it should rest below C, and when it first starts, all of the gauges make a full sweep and then return to their proper places. If it's not going to C, then there may be some schmutz interfering with its movement, or the needle has somehow moved, but I think that's very unlikely.