As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - FLIGHT 2544, RETURN TO THE GATE WITH FUEL IMBALANCE. LEFT WING SHOWING 600 LBS HEAVY. CORRECTED ON TAXI. TURNING TO RUNWAY RIGHT WING WAS 600 LBS HEAVY THEN RETURNED TO NORMAL. AT ARRIVAL BACK AT GATE RT IMBALANCE RETURNED. MAINTENANCE REPLACED THE FUEL QUANTITY GAUGING COMPUTER. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.