As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EQUIPMENT COOLING "VALVE" LIGHT ILLUMINATED. "STBY" SELECTED & "VALVE" LIGHT REMAINED ILLUMINATED. REF MM 21-58-00, FIG 105, BLOCK 1. TROUBLESHOOT IAW AMM. VALVE DETERMINED TO BE IN CORRECT POSITION SUPPLY TEMP SENSOR AND INLET FILTER CLEANED. NO WARNINGS PRESENT, NOW OK FOR SERVICE.