As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 239 PHX-DTW - SMOKE - FLIGHT DIVERTED TO DEN DUE TO SMOKE IN THE COCKPIT. MAINTENANCE FOUND EVIDENCE OF ELECTRICAL ARCING ON PILOT'S MAP LIGHT 25LE ALONG WITH BURNT ELECTRICAL SMELL INTERNALLY. REPLACED MAP LIGHT ASSEMBLY IAW AIRBUS MAINTENANCE MANUAL 33-12-12.