As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
L VALVE WING ANTI ICE ILLUMINATED AFTER SELECTING IT ON AT 19,000' TURNED IT BACK ON AROUND 9000' AND IT DID NOT RE-ILLUMINATE. GROUNDED - YES. REF B737-9 IFIM TASK 30-11-00-810-808 VALVE OPERATES SMOOTHLY. PERFORMED WING THERMAL ANTI ICE VALVE OPS TEST REF B737-9 AMM 30-11-11. OPS NORMAL. GROUND VERIFICATION GOOD.