As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
JUST AFTER TAKEOFF, THE CREW RECEIVED A WING ANTI-ICE CAUTION MESSAGE. TO AVOID FLYING INTO POTENTIAL ICING CONDITIONS, THE CREW LEVELED OFF AT FL030 TO RUN THEIR QRH. THEY DECIDED TO RETURN TO FIELD. NO EMERGENCY WAS DECLARED. REMOVED AND REPLACED LT WING A/I INBOARD TEMPERATURE SENSOR IAW CRJ900 AMM 30-12-06-000/400-801. OPS CHECK GOOD.