As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ANTI-ICE DUCT WARNING OCCURRED ABOUT FL260. PERFORMED QRH PROCEDURE AND MESSAGE CONTINUED INTERMITTENTLY. RETURNED TO DFW. MESSAGE WENT OUT PRIOR TO LANDING. REMOVED AND REPLACED NR 15 SENSOR IAW MM 36-21-07. REMOVED AND REPLACED LEFT BLEED CONTROL UNIT IAW MM 30-12-19. OPS CHECK GOOD. P/N OFF/ON 20-035008-067, S/N OFF A2286, S/N ON A1754.