As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW NOTED SMOKE IN THE CABIN AFTER APU START UP ON THE GROUND DURING PREFLIGHT INSPECTION. MAINTENANCE INSPECTED THE PLANE AND DETERMINED THAT THE APU WAS NOT RUNNING DURING DE-ICING AND INGESTED THE STRAY FLUID CAUSING THE SMOKE AND ODOR.