As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - DE-ICE PRESSURE ON DURING DESCENT (9 PSI) DURING TAXI PRESSURE RETURNED TO NORMAL (SELECTED BOOT AIR TO ISO AS PER CHECKLIST). REPLACED NR 1 & 2 LOW PRESSURE SWITCHES (55) PERFORMED FUNCTIONAL CHECK OF BLEED AIR SYSTEM IAW AMM 21-11-00, PAGES 501-503. OPERATIONAL CHECK GOOD. NO DE-ICE PRESSURE CAUTION NOTED. AIRCRAFT RETURNED TO SERVICE.