As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON TAXI FOR DEPARTURE THE CREW OBSERVED A NR 2 CARGO PIT CAUTION INDICATION. THE AIRCRAFT RETURNED TO COMPANY RAMP WHERE MAINTENANACE DETERMINED THE SMOKE DETECTOR SYSTEM CONTROL ELECTRONICS UNIT IN THE NR 2 PIT WAS AT FAULT. THE UNIT WAS REPLACED AND THE AIRCRAFT WAS RETURNED TO SERVICE. (TC NR 20061011008)