As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON MASTER RECALL FOR THE DESCENT CHECK AT CRUISE THE LEFT PACK LIGHT ILLUMINATED. PACK LIGHT EXTINGUISHED UPON RESETTING THE MASTER CAUTION. GROUNDED - YES. ACCOMPLISHED B737-900 FIM TASK 21-53-00-810-809, LEFT PACK LIGHT RESETS, OPERATED LEFT PACK COOLING SYSTEM AND OPERATES NORMAL. PACK /ZONE TEMP CONTROLLER BITE TEST PER B737-900 AMM TASK 21-61-00-700-806-002 NO CURRENT FAULTS, OPS CK GOOD.