As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#1 ENGINE ANTI-ICE, TAI LIGHT, ILLUMINATED AMBER WITH #1 ENGINE COWL VALVE OPEN LIGHT ILLUMINATED "BRIGHT BLUE" WHEN ENGINE ANTI-ICE WAS SELECTED TO ON DURING DESCENT. DURING CHECKLIST TAI 0 COWL VALVE OPEN LIGHT RETURNED TO NORMAL. DURATION OF LIGHTS APPROX 3 MINS. GROUNDED - YES. REMOVED AND REPLACED #1 ENG COWL TAI VALVE REF AMM TASK 30-21-11-000-801 AND TASK 30-21-1-400-801. INSTALLATION TEST GOOD REF AMM TASK 30-21-11-860-009. RAN #1 ENG REF AMM TASK 71-00-00-800-807-F00 GND VERIFICATION.