2006 GMC Canyon says its overheating but it's not!

I have a 2006 GMC Canyon which says its overheating but it’s not. I’ve changed the temperature sensor but it still does it! What else can I try?
It has no check engine light on!

It may just be a faulty temp gauge in the dashboard. I had that happen once, gauge went “hot” for no apparent reason, and replacing the gauge solved the problem.

However, just to double check, you can have a mechanic put a scanner on the computer and read the coolant temp sensor output. If the output is a normal running temperature but the dash gauge is in the “hot” zone, you’ve confirmed the gauge is faulty.

About how much was that to replace?

I bought a scan gauge & haven’t put it on it yet! Would that work?

Depends on the scan tool, but coolant temp is a pretty basic parameter, so chances are good your scanner will be able to read it.

When my temp guage went bad it was under warranty, so I don’t know how much it cost. Main problem is the labor hours it takes to remove the dashboard.

I've changed the temperature sensor but it still does it!

Are you certain you changed the temperature associated with the gauge? On my Corolla (of an earlier vintage ) there’s 3 coolant temp sensors screwed in at various places, one for the dash gauge, one for the computer to use, and one for the cold start injector. And there’s emissions port-control gadgets that are coolant temp based too. So it’s easy for a diy’er to get confused which is which.

On newer cars they’ve tried to eliminate all but one coolant temp sensor and let the computer control everything, like the gauge and the cold start system, but for your 2006 Canyon, I’m not sure of that engine’s configuration. Do you know?

Also, when you say the engine isn’t overheating, on what basis do you make that judgment? You might want to get a shop to test that assumption, as if you are wrong it could actually be overheating and damage the engine. Perhaps it is actually overheating but not yet producing any symptoms you are noticing. Be sure to check the coolant level both in the overflow bottle and in the radiator. If any work has been done on the cooling system recently you may have some air trapped inside now, and that can cause overheating. One idea, if the coolant is due for replacement, anyway now’s a good time to do that. New coolant and bleeding the cooling system of air, and maybe a new radiator cap and thermostat, that might solve the problem.