As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 2265 - MKE-GRR - DURING TAKEOFF, THE CREW GOT A LEFT PACK INOPERATIVE CAS MESSAGE, CONSULTED WITH MAINTENANCE BUT WERE UNABLE TO GET THE MESSAGE TO CLEAR. THE A/C RETURNED TO THE GATE. MAINTENANCE REPLACED THE LEFT HIGH PRESSURE VALVE (PRSOV) BUT THE PROBLEM REMAINED. MAINTENANCE THEN REPLACED THE OXYGEN/ECS PANEL AND ALL OPERATIONAL CHECKS WERE GOOD. WITH NO FURTHER DISCREPANCIES NOTED THE A/C WAS RETURNED TO SERVICE. (M)