As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI OUT, NR 1 ENGINE ANTI-ICE VALVE LIGHT ILLUMINATED; FOLLOWED ABNORMAL PROCEDURE; RETURN TO RAMP. REMOVED AND REPLACED NR 1 ENGINE RT ANTI-ICE VALVE IN ACCORDANCE WITH MM 75-10-1; OPERATIONAL CHECK IN ACCORDANCE WITH MM 75-10-0 AND MM 71-0 FOUND NORMAL.