Note. If DTCs P0117 and/or P0118 are present, trouble shoot DTC P0116 last.
Start engine and run at 3000 RPM with no loads and transmission in Park or Neutral until radiator fan comes on. Allow engine to idle. Check ECT sensor using OBD-II scan tool. If 176-200°F (80-93°C) is indicated, problem is intermittent. System is okay at this time. Check cooling system. If 176-200°F (80-93°C) is not indicated, check cooling system. If cooling system is okay, replace ECT sensor.