As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD INFLIGHT - ANTISKID LIGHT ILLUMINATED ON TAKEOFF ROLL AROUND 100 KNOTS. EXTINGUISHED ON LIFTOFF. RETURNED TO ORD AND LANDED WITHOUT INCIDENT. ANTISKID LIGHT DID NOT ILLUMINATE ON TOUCHDOWN OR ROLLOUT. REPLACED ANTISKID AUTOBRAKE CONTROL ASSEMBLY UNIT. SYSTEM GROUND CHECKED NORMAL OPERATION.