What was found
AIR TEMP GAUGE DISPLAY ERRONEOUS TEMPS FOR SUPPLY DUCT, PAX CAB AND PACK READINGS. ALL INDICATIONS SHOWED 29 DEG C OR HIGHER, BUT FLIGHT ATTENDANTS COMPLAINED IT WAS COLD ESPECIALLY IN THE AFT. ACFT GROUNDED. CLEANED THE CABIN TEMP SENSOR FAN FILTERS. RAN PACKS, TEMP GAUGE DISPLAY CORRECT TEMPS FOR WHATS SELECTED. NO FAULTS ON PACK TEMP CONTROL NR 1. OR 2. ZONE TEMP CONTROLLER FAILED PREVIOUS FLT, BUTTON INOPERATIVE. REMOVED & REPLACED THE NR 2 PACK TEMP CONTROLLER IAW MM 21-61-20.