As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PRIOR TO START, PILOT NOTED SMOKE AND BURNT ODOR IN AREA OF THROTTLE QUADRANT WITH SHIPS BATTERIES ON.MAINTENANCE DID TROUBLESHOOT AND DISCOVERED ODOR TO BE FROM GPS CONTROL UNIT IN PEDESTAL (GPS WAS INOPERATIVE) GPS UNIT WAS REMOVED FOR REPAIR AND AIRCRAFT DEFERRED FOR REMOVED GPS. AC RETURNED TO SERVICE.