What was found
(CAN) PILOT REPORT: `DURING T/O ROLL RWY23L ACCELERATED TO APPROX 100KTS: A/T WENT OFF WITH A CONTINUOUS AURAL WARNING WITH AMBER A/T INDICATION IN FMA.GO DECISION WAS MADE AT V1 (AUTO V1 CALL WAS INHIBITED). RE-SELECTION OF A/T WAS NOT SUCCESSFUL (PUSHBUTTON ON MCP). PROBABLY AFTER ROTATION & GEAR UP FMA MODES CHANGED TO APP FMS 1 AND FPA +1.5 INITIALLY. CONSEQUENCE WAS FD SHOWED NOSE DOWN COMMAND. WRONG MODE`S WERE CHECKED AND CORRECTED ACCORDINGLY. FMS1 AND VFLC SELECTED. A/T DISCONECT BUTTON (ON THRUST LEVERS) PRESSED. AMBER A/T INDICATION AND AURALS DISAPPEARED. A/T REENGAGEMENT VIA MCP PUSHBUTTON SUCCESSFUL.