As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT PACK PRODUCES A STRONG BURNING SMELL ASSOCIATED WITH SMOKE IN THE CABIN DURING INITIAL DESCENT. ISOLATED THE LEFT PACK BY SELECTING OFF AND CONDITIONS DISSIPATED AFTER 2-5 MINUTES. NO FURTHER OCCURANCE WAS NOTED. (FLT 2825) GROUND RAN LEFT PACK WITH APU AND NR 1 ENGINE IN ALL CONFIGURATIONS AND LEFT PACK OPERATES NORMAL. SUSPECT NR 2 ENGINE IS CAUSING OIL BURNING SMELL IN BLEED SYSTEM.