As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAINT LIGHT ILLUMINATED ON OVERHEAD PANEL. GROUNDED - YES. PERFORMED B737-9 IFIM 21-51-00-810-818 AND SYSTEM TEST PASSED. NO FAULTS DETECTED AND NO FAULTS PRESENT. VERIFIED PACK TEMP CONTROL VALVES ALL OPERATE NORMALLY PER B737-9 AMM 21-00-00.