What was found
*** EMERGENCY DECLARED *** SDR FILED OPEN *** FL 370 CABIN ALT EICAS MESSAGE MODE SELECT WAS AUTO 2 WITH BOTH PACKS IN AUTO. CABINDIFFERENTIAL WAS APPROXIMATELY 6PSI AND CABIN ALTITUDE INDICATED 11,00-12000 FEET (SEE PHOTO FOR REMAINING WRITE-UP) PERFORMED FIM 21-31 FAULT TREE 803. NO FAULTS NOTED ON EITHER CABIN PRESSURE CONTROLLER. R&R CABIN PRESSURE SELECTOR PANEL PER AMM 21-31-01 AND #2 OUTFLOW VALVE ACTUATOR PER AMM 21-31-05, PRECAUTIONARY PER FIM. OPS CHECK OF BOTH WERE NORMAL.