As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PNEUMATIC LOW PRESSURE DURING CLIMB AT LEFT ENGINE. CAPTAIN REPORTED THAT DURING CLIMB, PNEUMATIC LOW PRESSURE BELOW 18 PSI AT LEFT ENGINE. MAINTENANCE PERSONNEL PERFORMED ENGINE DUCT PRESSURE LOW TEST IAW FIM 36-10 TASK 807 PROCEDURE, DETECTING THE PRSOV VALVE WITH PNEUMATIC LEAK; SO THE PRSOV VALVE WAS REPLACED IAW AMM 36-11-04, TESTED CORRECT.