C172 PLT LOSES GPS AND BECOMES DISORIENTED IN THE FLL AND FXE AREA.

Narrative

I WAS FLYING FROM KEY WEST TO FORT LAUDERDALE EXECUTIVE (FXE) WHEN MY GARMIN 195 FLASHED AN UNFAMILIAR ERROR MESSAGE. THE GPS APPEARED TO BE WORKING FINE. AS I CONTINUED TO FLY N; I CONTACTED FORT LAUDERDALE INTL. THEY ASKED ME TO SQUAWK XXXX AND IDENT. THEY REPLIED 'WE SHOW YOU 7 MI SE OF THE ARPT.' AT THIS POINT I KNOW MY GPS IS NOT WORKING AND THERE ARE A LACK OF OTHER NAVAIDS AVAILABLE TO ME. ADDITIONALLY; I AM 6 MI OFFSHORE ON A FAIRLY CLOUDY NIGHT. I FEW MINS LATER; MY PAX IN THE BACK SEAT INDICATED WE HAD PASSED THE ARPT. I ASKED IF HE WAS SURE AND HE INDICATED THAT THE ARPT WAS DUE W OF A GROUP OF BUILDINGS ALONG THE SHORE. I CONTACTED FORT LAUDERDALE TWR AND CANCELED FLT FOLLOWING; SQUAWKED VFR (1200); LISTENED TO FXE ATIS; CONTACTED FXE TWR AND RPTED THIS TO THE NE INBOUND WITH ATIS INFO. THEY INSTRUCTED ME TO ENTER MIDFIELD FOR L DOWNWIND. AS WE GO OVER THE SHORELINE MY PAX INDICATES HE'S NOT SURE WHERE THE ARPT IS. I CALL FXE TWR AND HE DIRECTS ME TO FLY N. A COUPLE MINS LATER I SEE THE ARPT; CALL FXE TWR AND HE DIRECTS ME TO ENTER MIDFIELD R DOWNWIND. WE DID AND WE WERE ASKED FREQ WITH LAUDERDALE INTL TWR. I SHOULD HAVE REMAINED ON RECEIVED VECTORS TO FXE!