As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) UPON LANDING GEAR RETRACTION, FLIGHT CREW NOTICED THREE RED LIGHTS IN THE LANDING GEAR PANEL, QRH WAS FOLLOWS, AND FLIGHT CREW PERFORMED AN AIR TURN BACK FOR A NORMAL LANDING. MAINTENANCE CONFIRMED NW CENT PROX SENSOR READING FAR. PROXIMITY SENSOR ADJUSTED AND AIRCRAFT RETURN TO SERVICE.