A/C Calibration (Caravan, Town & Country, & Voyager): Procedure

Turn the ignition switch to the ON position. Simultaneously depress and hold the Power and Recirculation buttons on the heater-A/C control for at least five seconds. The manual heater-A/C control power Light Emitting Diode (LED) and Recirculation LED, or the Automatic Temperature Control (ATC) heater-A/C control Delay and Recirculation graphics will begin to flash when the calibration procedure has begun.
The calibration procedure should take less than two minutes to complete, for the manual heater-A/C control, and less than twenty seconds for the ATC heater-A/C control. When the LEDs or graphics stop flashing, the calibration procedure is complete.
If the LEDs or graphics continue to flash beyond the normal three minute (manual) or twenty second (ATC) calibration time, it indicates, that the heater-A/C control has detected a failure and a Diagnostic Trouble Code (DTC), has been set. Use a DRBIII® scan tool to perform further diagnosis.
The LEDs or graphics will continue to flash, even after the ignition switch is cycled Off and On, until a successful calibration is completed or until the vehicle has been driven about 8 miles. For diagnostic procedures for calibration test failure, see SELF-DIAGNOSTIC SYSTEM in appropriate AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.