As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN TAMP GAUGE INDICATES VERY LOW IN ALL SUPPLY DUCT AND PASS CABIN SETTINGS. TEMP CONTROLLER WORKS FINE WITH SELECTOR SWITCHES IN NORMAL (USUAL) POSITIONS. ACTUAL AIR TEMP IS NORMAL, IT APPEARS TO BE A GAUGE ERROR ONLY. GROUNDED - YES. REMOVED AND REPLACED CABIN TEMP SELECTOR P5-10 PANEL REF AMM 21-61-07 AND CABIN TEMP INDICATOR REF MM 21-61-32, OPS CHECK NORMAL.