As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SMOKE-FUME EVENT W/APU ON - NO COCKPIT INDICATION. C/W NO-GO/ODI PREVENTION PROGRAM 2172 WITH NTF. C/W WC 0550-2001 STEPS 1-5 AND 8-10 WITH NTF. C/W ELIMINATION OF RESIDUAL ODORS WITH APU AS THE SOURCE PER A220 EFIM SOLUTION ID #1-8458. NO SMELLS DETECTED.