Possible Causes

ECM illuminates MIL and sets DTC P1217, when engine coolant temperature is excessively high. Possible causes are:

• Cooling fan.
• Defective radiator hose.
• Defective thermostat.
• Defective ECT sensor.
• Radiator plugged.
• Radiator cap.
• Defective water pump.
• Improper coolant mixture ratio.