As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#1 COWL ANTI-ICE CAUTION LIGHT ON PRIOR TO TAKEOFF. GROUNDED - YES. REMOVED AND REPLACED ENG #1 ENG COWL TAI VALVE PER B737-800 AMM 30-21-11. REPLACED ENGINE #1 ANTI-ICE PRESSURE SWITCH PER AMM 30-21-21. SYSTEM OPS CHECK NORMAL. ETOPS GROUND VERIFICATION IS SUCCESSFUL.