As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STRONG ENVIRONMENTAL SMELL IN COCKPIT LEAVING FL380 TO FL360, DIVERTED TO LAS. REMOVED AND REPLACED THE FORWARD ENVIRONMENTAL CONTROL UNIT'S ACM C/W OPERATIONAL AND LEAK CHECK WITH NO DEFECTS NOTED AT THIS TIME. ALL MAINTENANCE PERFORMED IAW CESSNA CITATION 750 AMM 21-51-00.