As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 2 ENGINE AIR FAULT AND ENGINE NR 2 AIR VALVE CAME ON 5 MINUTES AFTER ENGINE AIR WAS SELECTED ON. FOLLOWED QRH PROCEDURES, SAME RESULTS. RETURNED TO DTW. MAINTENANCE REPLACED NR 2 ENGINE TEMP SWITCH IAW AVRO AMM 36. OPS CHECKED GOOD.