As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAXI OUT, THE CABIN AND FLIGHT DECK BEGAN TO FILL WITH SMOKE. ASSOCIATED WITH AIR CONDITIONING PACKS. OPERATED BOTH PACKS ON GROUND WITH ENGINE AND APU BLEEDS. FOUND WHEN PACKS SET TO COLD SETTING BOTH PACKS WOULD EMIT SMOKE. TURNED TEMPERATURE SETTING UP AND SMOKE CEASED.