As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CONT CAB ZONE TEMP LIGHT ILLUMINATED ON TAXI OUT. ACFT GROUNDED. ZONE TEMP CONTROLLER NR 2 SHOWS FLT DECK TRIM VALVE FAULT ON BITE AND PREVIOUS FLT. REPLACED CONT CAB ZONE TEMP VALVE AS REQUIRED. OPS CHECKED GOOD, REF AMM 21-61-21-400-801.