As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAXI TO THE GATE, EXCESSIVE BLUE COLORED SMOKE STARTED POURING OUT OF APU. *S/D* THE TURBINE SCAVENGE PUMP FAILED AND CAUSED THE SMOKE OUT OF THE APU TAILPIPE DUE TO OIL NOT BEING SCAVENGED BACK TO THE GEARBOX. REPLACED THE SCAVENGE PUMP.