As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#1 ENGINE ENG ANTI ICE COWL VALVE LIGHT ILLUMINATED TWICE. TURNED OFF WENT OUT. TURNED ON CAME BACK. GROUNDED - YES. CHECKED OMF FOR ANY EXISTING FAULT AND FOUND NO RELATED MAINT MSG. ACCOMPLISHED B737-9 IFIM TASK 30-21-00-810-807 COWL ANTI-ICE VALVE TEST GOOD. REPLACED ENG ANTI-ICE MINIMUM PRESS SWITCH REF B737-9 AMM 30-21-21 OPS CK SWITCH GOOD. RUN #1 ENG AND OPS TEST OK REF AMM 30-21-00-710-801.