As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX- DE-ICE PRESSURE CAUTION LIGHT IN FLIGHT. ISOLATED SYSTEM AS PER CHECKLIST. ALL BOOT INDICATIONS NORMAL EXCEPT NO.2 INBOARD TAIL BOOT ILLUMINATED LATE AND STAYED ILLUMINATED LONGER THAN NORMAL. DE-ICE PRESSURE INDICATED 17 PSI ON NO.1 AND 21 PSI ON NO.2. REMOVED AND REPLACED NO.2 LOW PRESSURE WARNING SWITCH. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.