Have a 2012 equinox with ac problem. It would blow cold then it would go warm. Now its blowing hot. I thought it was low on freon but it's full. Hook up scan tool. The scan tool is showing -31° on the HVAC ambient temp. So I can only assume this sensor is bad but alldata is telling me it's in the ac/heater box. I swapped that sensor same reading. Anyone know if that sensor is in the headliner above drivers head ?

 

How did you determine that your A/C system was OK IRT the R-134 refrigerant levels and pressures?

 

I have a robinair evacuate and charge machine. It takes 1.43 lbs and that's what evacuated.

 

I was thinking it's the cabin temp sensor because it's showing -31°.

 

You are way ahead of most people who ask about A/C issues here. Could easily be the cabin temp sensor, I agree.