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Home >> GMC >> 1999 >> C 2500 Truck 2WD V8-5.3L VIN T >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Scan Tool Testing and Procedures >> Scan Tool Data, Normal Values and Definitions >> Scan Tool Data Definitions - Powertrain Systems >> HVAC in Recirculation Mode
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HVAC in Recirculation Mode

The scan tool displays Yes or No. This parameter displays the PCM's commanded state of the recirculation door not the HVAC controller's commanded state. Changing the state of the recirculation door, via the HVAC control head, does not affect this parameter. This parameter changes from No to Yes when the Secondary A/C High pressure switch closes for a predetermined time.
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