PLT OF PA46 NEGLECTS TO REPROGRAM HIS GPS WHEN GIVEN A CLRNC TO A FIX OTHER THAN HE HAD ENTERED.

Narrative

AS I APCHED FIM I WAS HAVING DIFFICULTY HEARING APCH AND ALSO ASKING FOR APCH'S INTENTIONS FOR ME PAST FIM. AS I WAS ADJUSTING SQUELCH AND CHANGING COM RADIOS I HEARD THAT I WAS CLRED DIRECT TO THE 'COOGA' FIX. I HAD ALREADY LOADED THE GPS RWY 26 TO CAMARILLO INTO MY KLN90B. AT THAT POINT I SELECTED OBS MODE; SET THE COURSE POINTER TO 247 DEGS AND CHANGED THE OPERATING MODE OF THE FIX FROM 'DIRECT' TO 'ACTIVE.' AS I STARTED TO INTERCEPT THE 247 DEG RADIAL APCH CALLED AND ASKED IF I WAS ON THE GPS APCH. IT WAS THEN THAT I NOTICED THE 'ACTIVE' FIX WAS FIM AND NOT 'COOGA' RESULTING IN MY STARTING TO FLY THE INTERCEPT TO A PARALLEL ABOUT 7 NM N OF THE INTENDED RADIAL. APCH GAVE ME A VECTOR TO FLY AND I RECONFIGURED THE KLN90B AND COMPLETED THE APCH NORMALLY. CONTRIBUTING WAS THE STRESS DUE TO COMMUNICATING WITH APCH; CONCERNS ABOUT MY CLRNC AFTER FIM; AND FATIGUE AFTER NEARLY 5 HRS ENRTE AND FAILURE TO DOUBLE CHK THE FIX ACTIVATED AFTER DOING SO. THIS IS ALSO THE EXACT POINT AT WHICH CTL IS XFERRED AMONG LCL APCH CTLRS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES THE ACFT WAS A PA46; PIPER MALIBU. THIS WAS HIS OWN ERROR IN NOT RESETTING THE PROPER FIX INTO THE GPS. HE PARTICIPATED IN THE GPS CALLBACK QUESTIONNAIRE/SURVEY.