Home >> Mercury >> 2005 >> Montego Base, AWD >> Repair and Diagnosis (Single Page) >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> HVAC Control System - General Information >> Diagnosis And Testing >> Climate Control System >> Pinpoint Tests >> Pinpoint Test F: No Communication With The Electronic Automatic Temperature Control (EATC) Module >> Possible Causes