Sorry for the delay as I had a family emergency.

If the a/c has a full charge and the pressures are within spec we need to look at the heater valve/valve circuit side of the system. Here is a good test to determine if it is the module or a wiring problem as if the one side of the valve loses signal it will default to full heat so if the wire is broken from the module to the climate control head you will have this problem. Go to the driver side dash and remove the side panel. You will see some connectors. We are looking for the gray connector. Use a light and you will see each wire pin numbered. You are looking for the 12 way gray connector. Make sure the key is off and with a voltmeter check for power on pins 11 (brown/green) and pin 12 (brown/blue). If power is present on both wires then the wiring is good and you then need to leave the black lead of your meter to ground and start the engine and turn the climate control to full a/c. You should read low voltage on both pins and you should see it change as you increase/decrease the temp on both pins. If the voltage stays high you have a bad module and the valve is most likely shorted.