As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKEOFF ROLL, AT APPROXIMATELY 75 KTS, CREW RECEIVED A NR 2 PACK OVERHEAT MESSAGE. THE TAKEOFF WAS ABORTED AND AIRCRAFT RETURNED TO THE GATE. MAINTENANCE FOUND THE RIGHT AUTOMATIC TEMPERATURE CONTROLLER AT FAULT CAUSING SYSTEM TO PRODUCE ONLY FULL HOT AIR.