Since no data seems to be available, I'm wonderig if my wiring is faulty. (I had the same result with my Mega)
As you can see in the datasheet the GPS has 6 pins. The PPS and backup VDD are not in use in my wiring.
I hooked the RXD to RX (as defined in the SoftwareSerial) and the TXD to TX. VDD goes to 3V3 and GND to GND. Is there anything I could measure to test? (there is power on the GPS)