As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT NR 3528,NR 4 ENG INTAKE LO PRESS ILLUMINATES WITH ENG ANTI ICE SELECTED ON AT HIGH POWER LOW PRESS EXTINGUISHES WHEN POWER IS REDUCED. AIR RETURN TO DTW. MAINTENANCE REMOVED AND REPLACED VALVE P/N 2351A000 S/N ON 922300-7 S/N OFF 760380-3 PERFORMED GN RUNS ALL CK'S GOOD IAW AVRO AMM.