As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FORWARD CABIN TEMPERATURE VERY WARM, ESTIMATE 90 DEGREES WITH TEMPERATURE SELECTOR IN FULL COLD POSITION. COMPLIED WITH QRH PROCEDURE AND SELECTED TRIM AIR OFF. TEMPERATURE IN CABIN RETURNED TO NORMAL. ACFT GROUNDED. COULD NOT DUPLICATE MALFUNCTION. PZTC LOGGED, NO FAULTS & BITE CK WAS GOOD. TEMPERATURE RESPONDED NORMALLY DURING PACK OPERATION. R & R FWD ZONE TRIM VALVE. OP CK NORMAL. REF MM 21-61-21.