As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DTW - FLT 3631 - LEFT INNER WING DE-ICE ILLUMINATED WITH SWITCH TURNED ON. CYCLED SWITCH SEVERAL TIMES VALVE WILL NOT OPEN, RETURNED TO DTW. MAINTENANCE REPLACED NR 2 ENGINE DE-ICE VALVE FOR LEFT INNER WING. OPS CHECK GOOD. ALL IAW 30-11-17. (M)