To decide this error you need to extract the Refcode from the SNS (SCSI Sense Data). The last 4 digits of the third to last grouping of numbers is the refcode - in this case E475.  If you look in the DMX4 Product Guide for that error you'll see it translates to "One of the mirror 2 devices not ready (env_test9)."
what means G1 0014 0P64I R  MAINT REQD SYS098=B5B                  CCSW=63D097559802000000 CCB=975558 SK=000080000000  SNS= 00001F10 5B328F5B 33800000 00020514 0700044A1142E475  05100200 FE000000? on symmetrix DMX-4                                                                                                                
G1 0014 0P64I R MAINT REQD SYS098=B5B