As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CONT CAB ZONE TEMP ILLUM ON RECALL. RAN QRH AND THE LIGHT EXTINGUISHED. GROUNDED-YES, PER B737-800 FIM 21-62 TASK 842 PZTC NR 2 SHOWED RED LIGHT "FLIGHT DECK TRIM VALVE" DURING BITE TEST. AFTER RESET, PERFORMED BITE TEST, NO FAULTS NOTED.