As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INTERMITTENT ILLUMINATION OF LEFT INTAKE CAUTION LIGHT ON CLIMBOUT FROM DTW. LIGHT CYCLES ON FOR 2 - 7 SEC, THEN OFF 5 - 15 SEC, LIGHT DID NOT CYCLE ON DESCENT BACK INTO DTW. MAINTENANCE REPLACED LEFT DEICE CONTROL MODULE. PERFORMED OPERATIONAL CHECK OF LT INTAKE. OPS CHECK GOOD IAW SAAB AMM 30-20.