As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ETOPS SIGNIFICANT SYS - AFT CABIN TEMP INDICATION IS APPROX 20 DEG TOO HIGH, FWD AND MID SHOW APPROX 73 AFT 93, F/A'S REPORT TEMP FEELS NORMAL. FOUND AFT CABIN TEMP SENSOR DIRTY AND NO FLOW ACROSS SENSOR. CLEANED BOTH LINE AND SENSOR CHECKS OK.