As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER LANDING DURING TAXI IN, A SLIGHT BURNING RUBBER ODOR WAS NOTICEABLE. ( BOTH ENGINES AND APU RUNNING) AFTER ENGINE SHUTDOWN, APU STILL ON, THE ODOR GOT VERY STRONG AND CABIN STARTED TO FILL WITH SMOKE. ODOR AND SMOKE CLEARED AFTER COMPLETE SHUTDOWN. REMOVED AND REPLACED CABIN ACM WITH A REPAIRED UNIT. PERFORMED OPERATIONAL TEST OF THE ECU. OPS CHECK GOOD. ALL WORK DONE IAW MM 21-51-00.