As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
L PACK CAUTION LIGHT ON RECALL DOES RESET. GROUNDED - YES. PERFORMED L/H PZTC BITE REF B737-800 AMM 21-51-00. FOUND TCV FAULT LIGHT ON BIT AND ALL PREV FLT. IN VERIFY L/H TCV IS VERY LOUD. REMOVED AND REPLACED L/H TEMP CONTROL VALVE REF B737-800 AMM 21-51-10. OPS AND LEAK CK GOOD. PZTC BITE CK GOOD-NO FAULTS. PERFORMED CABIN TEMP CONT AND INDICATION OPERATIONAL TEST REF AMM 21-61-00. TESTS GOOD-NO FAULTS. ETOPS SIGNIFICANT SSTEM GROUND VERIFICATION SUCCESSFUL.