As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT APPROX 13,000 FT ON APPROACH, GOT AN "AMC O' HEAT" TEMP CAS MESSAGE FOLLOWED BY AN EMER PRESS ACTIVATION. SHORTLY AFTER EMER PRESS CAME ON CABIN STARTED TO AQUIRE SMOKE. IT GOT TO A "HAZY CLOUD" THICKNESS AND THEN STABILIZED. SMOKE SMELL ASSOCIATED. VERIFIED ACM O'TEMP CAS MESSAGE ON WITH ACFT PWR ON. REPLACED ACM OVER-TEMP SWITCH WITH NEW. OPS/LEAK CHECKS GOOD. DONE IN REF TO MM 21-51-00.