As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMBOUT AT 4000 FT RECEIVED A AUTO PRESSURIZATION FAIL LIGHT, ACCOMPLISHED QRH TASK AT 7000 FT, AUTO FAIL LIGHT DID NOT EXTINGUISH WITH CONTROLLER SET TO ALTN PER QRH AND CABIN CLIMB INDICATOR STILL INDICATED 1000 FT PER MIN WHILE LEVEL AT 7000. GROUNDED - YES. AIR TURNBACK - REMOVED & REPLACED AFT OUTFLOW VALVE ASSY, INSTALLATION TEST CHECK GOOD REF AMM 21-31-03.