As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMB OUT AND AFTER LEVEL OFF AT FL370, AIR CONDITIONER DUCT PRESSURE MORE THAN 20 PSI, RT SHOWED 18 PSI, LT SHOWED 42 PSI. ACFT GROUNDED. COMPLETED T/C NG-36WC-00001. FOUND PRECOOLER CONTROL VALVE FAILING STEP 3.F.5. R & R PRECOOLER CONTROL VALVE REF AMM 36-12-02. OPS CK NR 2 BLEED SYS REF FIM PB 36-10-00-301. NO HELP BLEED SPLIT 20 PSI WITH RT 18 PSI AND LT 32 PSI. R & R NR 2 PRECOOLER VALVE SENSOR. OPS CHECKED IAW FIM PB 36-10-00-301, OPS CHECKED GOOD.