What was found
AFTER TAXI, CONT CABIN ZONE TEMP LIGHT CAME ON, RESET WITH RECALL. GROUNDED - YES. PERFORMED B737-800 FIM 21-62 TASK 801 ON BOTH #1 AND #2 PACK ZONE/TEMP CONTROLLERS ON #2 PACK CONTROLLER FOUND FLIGHT DECK TRIM VALVE FAULT. RESET FAULT, FAULT CLEARED, REF FIM 21-62 TASK 832. INSPECTED F/D TEMP SENSOR. FOUND DIRTY FILTER AND SENSOR. CLEANED AND REPLACED FILTER. OPERATED PACKS WITH NO FAULTS ON MASTER RECALL.