As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RT INTAKE CAUTION LIGHT CAME ON AFTER TURNING ON. LIGHT CYCLED ON/OFF EVERY FIVE SECONDS. TEST OK ON THE GROUND BEFORE TAKEOFF. AIR RETURN TO DTW. MAINTENANCE FOUND CHAFED WIRE ON THE RT INTAKE EXHAUST NOZZLE. REPAIRED WIRE, ALL CHECKS GOOD.