What was found
ZONE TEMP LIGHT FOR CONT CAB CAME ON DURING TAXI OUT. ACCOMPLISHED QRH PROCEDURES. LIGHT EXTINGUISHED WITH MASTER CAUTION RESET. ACFT GROUNDED. PERFORMED FIM 21-62 TASK 842, INITIAL EVALUATION PASSED. PERFORMED PACK TEMP CONTROL BITE, NO EXISTING FAULTS. HOWEVER, ON LEG 3 MSG 21-51217, FLIGHT DECK SELECTOR OPEN FAULT, MSG 21-51220, ZONE SELECTOR OPEN FAULT, AND MSG 21-51311, FLIGHT DECK SELECTOR NON-RECOVERABLE, LOGGED ON PFTC, M2951 AND PFTC, M2952. ACCOMPLISHED GROUND TESTS ON BOTH PFTC, M2951 AND M2952, GROUND TEST COMPLETE, PASS WITH NO FAULTS, REF FIM 21-62, TASK 801. NO PREVIOUS HISTORY, THIS CLEARS MEL 21-21F CONTROL CAB ZONE TEMP LIGHT.