As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
L2 WINDOW OVERHEAT ILLUMINATED ON THE GROUND. GROUNDED - YES. PERFORMED SYSTEM TEST AND NO FAULTS FOUND. THE FAULT HISTORY ON CONTROL BOX FOR L2 WINDOW DID HAVE A SENSOR FAULT. REMOVED AND REPLACED L2 WINDOW IAW B737-800 AMM 56-12-11-000-801 AND AMM 56-12-11-400-801, ETOPS GROUND FUNCTIONAL CHECK GOOD. ALSO LEAK CHECK GOOD.