As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PAX IN 15 AND F/A NOTED ACRID ODOR. DETERMINED ODOR IS RESIDUAL FROM RECIRC FAN. SMELL CLEARED OUT WITH RECIRC FAN OFF. OPENED ALL CABIN DOORS AND VENTED OUT ACFT. GROUND RAN WITH BOTH ENGINE BLEEDS AND APU BLEEDS. ODOR CONTINUES TO DECREASE. VENTED CABIN AGAIN, NO SMELL IN CABIN. RETURNED TO SERVICE.