As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - AFTER TAKEOFF AND 5 SEC AFTER GEAR UP RECEIVED "PROX SYSTEM" MASTER CAUTION FOLLOWED BY "PROX SYS FAULT 2" STATUS MSG. RETURNING TO FIELD AT 20 MIN LATER ALTITUDE 14,000 BOTH MSG WENT AWAY. LANDING UNEVENTFUL. REPLACED PCB5 IN JB-3, REPLACED OF LANDING GEAR SELECTOR VALVE, AND REPLACED LANDING GEAR CONTROL PANEL. ALL OPS CHECKS GOOD. LEAK CHECK GOOD. COULD NOT DUPLICATE ABOVE DISCREPANCY. OPERATIONAL CHECK FLIGHT GOOD. RETURNED TO SERVICE.