Diagnostic Procedure
- Check engine coolant temperature sensor. See Figure . If okay, go to next step. If not okay, replace engine coolant temperature sensor.
- Let engine cool to less than 158°F (70°C). Grasp lower radiator hose and confirm engine coolant does not flow. If okay, go to next step. If not okay, repair or replace thermostat.
- Problem may be intermittent. See INTERMITTENTS under TROUBLESHOOTING - NO CODES article.