What was found
DE-ICE PRESSURE CAUTION ILLUMINATED IN FLIGHT. ALL BOOT SECTIONS APPEAR TO INFLATE NORMALLY. DE-ICE PRESSURE INDICATES NORMAL. DEICE PRESSURE CAUTION REMAINED ON AFTER CHECKLIST COMPLETED. DIVERTED, AND LANDING UNEVENTFUL. REMOVED FROM SERVICE. PERFORMED FUNCTIONAL TEST OF THE AIRFRAME DE-ICING SYSTEM IAW AMM 30-11-00-720-801. OPS TESTED GOOD. NO CAUTION LIGHT ILLUMINATED. THERE WERE NO RELATED FAULTS IN THE CDS. PERFORMED GVI OF ALL DE-ICE BOOTS WHILE THEY WERE BEING INFLATED. FOUND A HOLE IN THE LT INBOARD DE-ICE BOOT. REPAIRED THE LT INBD BOOT IAW AMM 30-11-00-300-802. REMOVED AND REPLACED THE TMU AS A PRECAUTION IAW AMM 30-11-00-01-000-801, AND 30-11-01-400-801. OPS CHECKED GOOD. AIRCRAFT RETURNED TO SERVICE.