As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED. ON TAKEOFF ROLL AT APPROXIMATELY 50 KIAS, MASTER CAUTION LIGHT ILLUMINATED WITH LEFT COWL ANTI-ICE. REJECTED TAKEOFF, LOW SPEED BRAKES NOT APPLIED. REPLACED NR 1 ENGINE COWL TAI VALVE WITH SERVICEABLE UNIT, IAW AMM 30-21-11-000-801. LEAK AND OPERATIONS CHECK GOOD.