As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
REJECTED TAKEOFF FOR AUTOFEATHER FAILING TO ARM ON TAKEOFF ROLL AND TAKEOFF WARNING HORN ALSO SOUNDED. NO ASSOCIATED CAUTION LIGHTS ILLUMINATED WITH WARNING HORN, CAPTAIN WAS CONFUSED ABOUT HISTORY. PERFORMED HI SPEED TAXI, DURING TAKEOFF CONFIGURATION ARMED AUTOFEATHER, WARNING HORN DID NOT SOUND OFF. NO DEFECTS NOTED AT THIS TIME. OK FOR SERVICE.