As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - FLIGHT 2545, AFTER TAKEOFF RECEIVED A DISPLAY COOL MESSAGE. RAN CHECKLIST BUT MESSAGE STAYED ON. RETURNED TO THE FIELD AND ACCOMPLISHED A OVERWEIGHT LANDING. MAINTENANCE REPLACED THE COOLING FAN AND PERFORMED A OVERWEIGHT LANDING INSPECTION. OPERATIONAL CHECKS GOOD FOR THE FAN AND NO DEFECTS FOUND ON THE OVERWEIGHT INSPECTION. AIRCRAFT RETURNED TO SERVICE.