As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON DESCENT WITH POWER AT IDLE "L VALVE" LIGHT FOR WING ANTI ICE CAME ON. TRIED AGAIN WITH POWER AT 65% N1 AND LIGHT REMAINED ON. GROUNDED - YES. ACCOMPLISHED B737-9 IFIM TASK 30-11-00-810-808. LH VALVE WING ANTI ICE. OPS CHECK NORMAL AFTER RESET.