As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT 2868 LT AIR VALVE LIGHT ILLUMINATED. AIR RETURN TO DTW. WEATHER CONDITIONS WARRANT THE RETURN. MAINTENANCE REMOVED AND REPLACED THE LT GARRET VALVE, (SWAPPED LEFT TO RIGHT AND PROBLEM FOLLOWED) IAW SAAB MM CH 75. OPS AND SECURITY CHECK GOOD.