As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CONTROL CABIN ZONE TEMP LIGHT ILLUMINATED ON TAXI OUT. PACK/ZONE TEMP CONTROLLERS PASS BITE PROCEDURE. OPENED A/C ZONE TEMP VALVE FAN CONT FLT DECK (B3 ON P6 4 PANEL). CLEANED FLIGHT DECK TEMP SENSOR. OPERATED AIR CONDITIONING SYSTEM. ZONE TEMP LIGHT NEVER CAME ON. REF AMM 21 61 06 000 801 FIM 21 62 00 810 842 FIM 21 62 00 810 801.