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 ILLUMINATES WITH MASTER CAUTION RECALL. CAUTION LIGHT EXTINGUISHES WITH MASTER CAUTION RESET. GROUNDED - YES. FOUND FAULT ON ZONE TEMP CONT #2,TRIM VALVE FLT DECK. PERFORMED BITE TEST PER B737-900 AMM 21-61-002, FAULT CLEARED, OPS CHK GOOD.