As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER ENGINE START UP AND WITH THE PACKS SELECTED ON, THE CABIN FILLED WITH SMOKE, ALONG WITH A R PACK AUTO FAIL MSG. MX T/S AND FOUND THE RT ACM TO BE THE ISSUE AND IT WAS DEFERRED. REMOVED AND REPLACED RH ACM. OPS CHECK GOOD. THIS CLEARS MEL.