Cool option :N
The only reason I said anything about the blend door is because that is normally what goes wrong with them, especially around the time when you haven't used it in a while and are going from one season to the next (switching from hot to cold).
you could always try the diagnostic on the climate control
"On-Board Diagnostic Test"
"NOTE:
The in-vehicle temperature should be greater than 50°F (10°C) for all DTCs shown to be valid."
"The control assembly will detect electrical concerns occurring during the On-Board Diagnostic."
"Ensure that the engine is warm, at least 120°F coolant temperature."
"To display the DTCs, initiate the On-Board Diagnostic by pushing OFF and FLOOR simultaneously and then AUTOMATIC within two seconds. The test may run as long as 20 seconds, during which time the display will be blank. If the display is blank for more than 20 seconds, go to System «Diagnosis When On-Board Diagnostic Indicates No Error Found."
"The On-Board Diagnostic Test can be initiated at anytime with the resulting DTCs being displayed. Normal operation of the system stops when On-Board Diagnostic is activated. To exit the On-Board Diagnostic and restart the system, push the BLUE button. The On-Board Diagnostic should be deactivated before powering the system down. Refer to the Diagnostic Trouble Code Key for an explanation of DTCs."
"DTC/SOURCE/ACTION"
"01/EATC control assembly./Replace EATC control assembly."
"02/Blend door concern./Refer to EATC Control Assembly Connector and Blend Door Actuator Diagnosis."
"03/In-vehicle temperature sensor/Refer to In-Vehicle open or short Temperature Sensor Diagnosis."
"04/Ambient temperature sensor/Refer to Ambient Temperature open or short Sensor Diagnosis."
"05/Sunload sensor short./Refer to Sunload Sensor Diagnosis."
"888/Testing complete/Refer to EATC System failure (all segments on Functional Check."
"No Heat (Blower Motor Functioning Properly)
Possible Source(s):
Coolant level.
Heater hoses.
Engine thermostat
Heater core.
Loose or improperly adjusted control cables."
